Solid Forms for Tissue Repair

ABSTRACT

This invention provides coral-based scaffolds for cartilage repair, and instruments for insertion and utilization of same within a site of cartilage repair.

BACKGROUND OF THE INVENTION

Defects and degeneration of the articular cartilage surfaces of jointscauses pain and stiffness. Damage to cartilage which protects joints canresult from either physical injury as a result of trauma, sports orrepetitive stresses (e.g., osteochondral fracture, secondary damage dueto cruciate ligament injury) or from disease (e.g. osteoarthritis,rheumatoid arthritis, aseptic necrosis, osteochondritis dissecans,avascular necrosis).

Osteoarthritis (OA) results from general wear and tear of joints, mostnotably hip and knee joints. Osteoarthritis is common in the elderlybut, in fact, by age 40 most individuals have some osteoarthitic changesin their weight bearing joints. Another emerging trend increasing theprevalence of osteoarthritis is the rise in obesity. The CDC estimatesthat 30% of American adults (or 60 million people) are obese. Obeseadults are 4 times more likely to develop knee OA than normal weightadults. Rheumatoid arthritis is an inflammatory condition which resultsin the destruction of cartilage. It is thought to be, at least in part,an autoimmune disease with sufferers having a genetic predisposition tothe disease.

Orthopedic prevention and repair of damaged joints is a significantburden on the medical profession both in terms of expense and time spenttreating patients. In part, this is because cartilage does not possesthe capacity for self-repair. Attempts to re-grow hyaline cartilage forrepair of cartilage defects remain unsuccessful.

Orthopedic surgery is available in order to repair defects and preventarticular damage in an effort to forestall serious degenerative changesin a joint. The use of surgical techniques often requires the removaland donation of healthy tissue to replace the damaged or diseasedtissue. Techniques utilizing donated tissue from autografts, allografts,or xenografts are wholly unsatisfactory as autografts add additionaltrauma to a subject and allografts and xenografts are limited byimmunological reactivity to the host subject and possible transfer ofinfective agents. Surgical attempts to utilize materials other thanhuman or animal tissue for cartilage regeneration have beenunsuccessful.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides a scaffold for repairof cartilage comprising coral having at least a first portion of anexposed surface raised with respect to at least a second portion of theexposed surface in the coral, wherein the first portion comprises atleast a region, which specifically positions and confines the coral atan optimal depth and angle within a site of cartilage repair.

In one embodiment, the present invention provides a method of inducingor enhancing cartilage repair, the method comprising implanting in asubject, a scaffold of this invention within a site of cartilage repair,wherein a region of the scaffold penetrates through a bone, resulting inthis region inserting within a bone marrow, proximal to the site ofcartilage repair.

In one embodiment, the present invention provides an instrument to aidin cartilage repair comprising at least one tool to guide a scaffold ofthis invention to an optimal depth at a site of cartilage repair, guidea scaffold of this invention to an optimal angle at a site of cartilagerepair, or a combination thereof, optionally at least one tool toprocess a scaffold of this invention following implantation within asite of cartilage repair, optionally at least one tool to effectpenetration of a scaffold of this invention through a bone, andinsertion within a bone marrow, proximal to a site of cartilage repairand optionally at least one tool to release a scaffold of this inventionat a site of cartilage repair, whereby said tool may be separated fromsaid scaffold following placement of said scaffold within a site ofcartilage repair.

In one embodiment, this invention provides a kit for repair of cartilagecomprising a scaffold of this invention, a tool of this invention, anddirections for utilizing the scaffold and the tool in tissue repair.

In one embodiment, this invention provides a scaffold for tissue repair,wherein the scaffold comprises a polymer form enveloping coralparticles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a longitudinal filled in view of an embodiment of ascaffold of this invention. The scaffold comprises first regions 1-20which are raised with respect to second regions 1-40, which first regionin some embodiments is proximal to avoid 1-30, which abuts the secondregion. FIG. 1B shows a similar longitudinal view. FIG. 1C shows abottom angled view of the scaffold in FIG. 1A, where the hollows 1-20are evident. FIG. 1D shows a cross section of an edge of the scaffold inFIG. 1C. FIG. 1E is a micrograph of a coral scaffold prepared, which hasa structure similar to that depicted in FIGS. 1A-1D.

FIG. 2A Shows a longitudinal filled in view of an embodiment of ascaffold of this invention. The scaffold comprises first regions 2-20which are raised with respect to second regions 2-40, which first regionin some embodiments is proximal to a void 2-30, which abuts the secondregion. FIG. 2B shows an angled view of FIG. 2A. FIG. 2C shows a similarlongitudinal cross-sectional view. FIG. 2D shows a cross section of anedge of the scaffold in FIG. 2C.

FIG. 3A shows an embodiment of a scaffold of this invention incross-sectional view. FIG. 3B shows an angled longitudinal filled inview of an embodiment of a scaffold of this invention and FIG. 3C showsa cross section along the Z axis of the scaffold. The scaffold comprisesfirst regions 3-20 which are raised with respect to second regions 3-40.

FIGS. 4A-F display three-dimensional images of scaffold geometries andlongitudinal cross-sections of each.

FIGS. 5A-5B are photographs depicting the preparation of embodiedscaffolds incorporating a polymer therewithin. FIG. 5A depicts fittingof the scaffold within a device used to prepare the polymer/coralscaffold, in this embodiment, a funnel and FIG. 5B depicts the effectiveselective incorporation within only a desired region of the scaffold.FIGS. 5C-5E depict various scaffold forms incorporating differentamounts of the polymer as a consequence of the timing of application, asfurther described hereinunder.

FIG. 6 is a photograph of another embodied scaffold of this inventionprepared as described herein, showing incorporation of the polymerwithin a specific region of the scaffold.

FIG. 7 is a photograph of various embodied scaffolds of the invention,which scaffolds have been dried by oven drying or lyophilization. Thevarious percentages of hyaluronic acid solutions applied to thescaffolds prior to drying are shown.

FIGS. 8A and 8B are photographs of scaffolds incorporating hyaluronicacid (HA) therewithin 8-10, following scaffold contact with solutionscontaining the HA at the indicated concentrations.

FIGS. 9A and 9B show implantation of a scaffold within a cartilagedefect site.

FIGS. 10A-10C depict an embodiment of a tool of this invention. FIG. 10Ashows a harvester 10-1 with a replaceable adaptor 10-4. The plunger orpiston 10-5 is shown, as well. The tool may further comprise anindicator 10-3, which serves to delineate the depth at which theinstrument is inserted. FIG. 10B shows a cross section along the longaxis of the tool, which shows in this embodiment, the presence of ahollow extending along the length of the tool. FIG. 10C shows aseparated view of the tool in FIG. 10A.

FIGS. 11A-11C schematically depict another embodiment of a tool of thisinvention, where the figure depicts, for example, a tool insert, whichmay be inserted in the Harvester shown in FIG. 10A. The insertion body11-2 depicted in FIG. 11A will further comprise a grooved hollow 11-3,which accommodates insertion of a scaffold as herein described withinthe hollow. The insertion body edge 11-4 is smooth. When the implant isloaded within the insert, the plunger or piston 11-1 pushes the implantout of the tool insert and into the site of repair, in for example, ahole made by the harvester of FIGS. 10A-10C. FIG. 11C shows a crosssection taken as indicated in FIG. 11B, showing positioning of thescaffold within the tool insert.

FIGS. 12A-12E schematically depict an embodiment of an adjustabledelivery system of this invention. FIG. 12A depicts an angled toolcomprising a plunger or piston 12-1 inserted in the body 12-2 of thetool, further comprising a joint 12-3, which can be either adjustable orreplaceable with a different angle parts, for example, as depicted inFIGS. 12B and 12C, showing 12-4, which can be a replaceable lockinghead. FIG. 12D provides an enlarged detailed view, where an adjustableor replaceable joint 12-5 is proximal to a groove, which may facilitateidentification of positioning of the implant during implantation, whichjoint 12-6 may comprise a rounded edge 12-7 to minimize the trauma totissue during implantation.

FIGS. 13A and 13B depict another embodied tool of the invention. FIG.13A shows a cross section along axis 13-1-13-2 of the tool, which toolis semi-elastic. The elastic spring, or other strong and elasticmaterial 13-3, transfers the force from the piston to the bit drill orto the inserted implant 13-4, as shown in FIG. 13B.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

This invention provides, inter alia, scaffolds, tools and methods of usethereof for repair of cartilage tissue in a subject. This inventionfurther provides kits for repair of cartilage tissue in a subject.

Coral, which is comprised of CaCO₃ in the crystalline form of calcite oraragonite, has the advantage of supporting fast cellular invasion,adherence, proliferation and differentiation of mesenchymal stem cellsinto cartilage tissue.

Three-dimensional (3-D) coral scaffolds attract mesenchymal stem cellsfrom bone marrow and promote blood vessel formation to a site ofcartilage repair. Such scaffolds can be used for regeneration ofcartilage in a subject for repair of partial or full-thickness cartilagedefects.

This invention provides the unexpected application of coral scaffoldingalone being useful in cartilage repair and moreover, that coralscaffolding can be prepared and inserted specifically and optimallywithin a site of cartilage repair for methods of cartilage repair.

The terms “coral” and “aragonite” and “calcite” are used interchangeablyherein.

In one embodiment, this invention provides a scaffold for repair ofcartilage comprising coral having at least a first portion of an exposedsurface raised with respect to at least a second portion of said exposedsurface in the coral, wherein the first portion comprises at least aregion, which specifically positions and confines the coral at anoptimal depth and angle within a site of cartilage repair.

In one embodiment of this invention, the first portion comprises atleast a region which specifically positions and confines the coral at anoptimal depth and angle within a site of cartilage repair providing anarrangement between a scaffold of this invention and a site of cartilagerepair which confers a benefit for cartilage repair.

In one embodiment, the term “specifically positions and confines thecoral within a site of cartilage repair” refers to positioning at anoptimal depth and angle by tight fitting, such that mechanical stress issufficient to orient the implant optimally, or in some embodiments, thepositioning is via a specific extension or protrusion of the scaffold,such that specific insertion into a region or wall of a tissue within arepair site, or within a site proximal to the repair site isaccomplished. In some embodiments, multiple scaffolds are insertedtherein, to optimally fill the defect site, or in some embodiments, tocreate a front or line along a defect site, leading from a region richin repair cells and/or materials to a site most distal thereto, within asite for which cartilage repair is necessary.

It will be apparent to one skilled in the art that the physical and/orchemical properties of a scaffold of this invention and componentsthereof may influence methods of use of this invention and kits thereof,for inducing or enhancing cartilage repair.

In one embodiment, methods of this invention for inducing or enhancingcartilage repair utilize the 3-D geometry of a scaffold of thisinvention to provide for specifically positioning and confining thescaffold within a site of cartilage repair.

In one embodiment, the phrase “positions and confines” refers to thecapacity of a region to secure a scaffold of this invention at aparticular location within a site of cartilage repair.

In one embodiment, a region comprises a subdivision of an area intowhich the whole or one of its parts is divisible. In one embodiment,regions may share characteristics with each other.

In one embodiment, a site of cartilage repair may be considered tocomprise a 3 dimensional (3-D) space at or proximal to a site of acartilage defect or potential defect. In one embodiment, this 3-D spacecomprises at least a wall or a floor, or a combination thereof, andpositioning within such a site may be described herein, relative to saidwall or floor, or in some embodiments, positioning may be relative toinsertion within a tissue site proximal to said wall or floor. In someembodiments, positioning include insertion of the scaffold or a regionthereof, past the wall and/or floor of cartilage tissue or a site ofdefect or injury or potential defect or injury in the cartilage tissue,such that insertion into bone tissue occurs. In some embodiments,positioning optimizes access to blood vessels and a bone marrow, mostproximal to the site of cartilage repair. In some embodiments, suchpositioning specifically inserts in a region within a bone marrow, whichis not proximal to the site of repair, yet is a site which is enrichedfor mesenchymal stem cells, which participate in the repair.

In one embodiment, at least a region of the scaffold positions andconfines the scaffold within a site of cartilage repair by forcefullycontacting tissue at a site of or proximal to cartilage repair, whereinthe scaffold is held in a specific position by the force of the regioncontacting the tissue. The force of contact between the scaffold and thetissue does not cause irreparable damage or unnecessary bleeding. Forexample if a site of cartilage repair is shaped like a cylindrical pitwith a single continuous wall and a floor, regions of the representativescaffolds depicted in the figures may, in one embodiment, forcefullycontact the tissue of the walls of the site to hold the 3-D scaffold inplace. In one embodiment of this example, a bottom region of a scaffold,abuts a floor of a site of cartilage repair. In an alternativeembodiment, forces exerted by regions of the scaffold contacting a wallof a site of cartilage repair hold and suspend the scaffold within thesite such that it does not contact the floor. In such a case, a regionof the scaffold may penetrate a wall of the site to reach a bone marrowvoid. In yet another embodiment, the forces exerted by the regions ofthe scaffold as described, position the scaffold such that if anadditional raised region of the scaffold is present, this region nowpenetrates through bone and is stably inserted within a bone marrow voidproximal to a site of cartilage repair.

In one embodiment, the term “proximal” refers to something beingsituated close to a particular locale. In one embodiment, a scaffold ofthis invention is forcibly held in position within a site of cartilagerepair by a raised region of the scaffold contacting tissue situated ator proximal to a site of cartilage repair.

In some embodiments, the region of the scaffold which penetrates throughbone and stably inserts within bone marrow is also the region of thescaffold which positions and confines the scaffold within a site ofcartilage repair, or in some embodiments, the region of the scaffoldwhich penetrates through bone and stably inserts within bone marrow isnot the region which positions and confines the scaffold within a siteof cartilage repair. FIGS. 1-3 show representative embodiments of ascaffold comprising a raised region Of the exposed surface. If the siteof cartilage repair is again shaped like a cylindrical pit with a singlecontinuous wall and a floor, in one embodiment the second portionregions insert through the floor or wall of the site, and therebypenetrates through bone and is stably inserted within bone marrowproximal to a site of cartilage repair. In one embodiment, the regioninserts through the floor or the wall so that the bottom of the mainbody of the scaffold makes contact with tissue at the site of cartilagerepair. In one embodiment, the region inserts in such a way that noother portion of the scaffold is in contact with tissue at the site. Inanother embodiment, the region inserts in such a way that the side wallsof the scaffold make contact with tissue at the site of cartilagerepair.

One skilled in the art will recognize that the shape of a site ofcartilage repair and the shape of a 3-D scaffold of this inventionprovide many different combinations for stably positioning a scaffoldwithin a site of cartilage repair. In one embodiment, a scaffold of thisinvention is shaped prior to use in methods of this invention forcartilage repair. In one embodiment, a scaffold of this invention isshaped concurrent to use in methods of this invention for cartilagerepair. By shaping a scaffold concurrent with use of the scaffold inmethods of this invention, the dimensions of the scaffold may beprecisely selected for specific positioning of the scaffold within asite of repair.

In one embodiment, a scaffold of this invention penetrates tissuesituated close to or near a site of cartilage repair to reach a bonemarrow proximal to the site of cartilage repair. In one embodiment,penetration of the bone marrow by a region of the scaffold positions andconfines the scaffold independent of other regions of the scaffold. Inone embodiment, penetration of the bone marrow by a region of thescaffold and forceful contact of at least an additional region of thescaffold with tissue at the site of repair together position and confinethe scaffold. In one embodiment, penetration of the bone marrow by aregion of the scaffold positions and confines the scaffold within a siteof repair while at least an additional region of the scaffold passivelycontacts tissue at the site of repair.

As described above, a scaffold's region's ability to position andconfine the scaffold of this invention is dependent on the region'sgeometry and the geometry at the site of cartilage repair where thescaffold will be implanted. In one embodiment, the region's geometrycomprises a sharp edge. In one embodiment, the region's geometrycomprises a rounded edge. In one embodiment, the region's geometrycomprises a jagged edge.

In one embodiment, this invention comprises multiple raised portionswith respect to other portions on the surface of a coral, and in someembodiments, at least a region of a multiple raised portion specificallypositions and confines a coral at an optimal depth and angle within asite of cartilage repair. In some embodiments, the region of multipleraised portions is more suited for cartilage repair, and in someembodiments, the region Which does not comprise raised portions is moresuitable for bone repair, and the scaffolds of this invention are insome embodiments, particularly suited for the repair of osteochondraldefects.

In one embodiment of this invention, an optimal depth and angle within asite of cartilage repair comprise the depth and angle most beneficialfor cartilage repair. In one embodiment, the optimal depth and anglemost beneficial comprise a position so that a scaffold of this inventionis accessible to a pool of mesenchymal stem cells, a tissue milieu,blood vessels, nutrients, an effector compound, or a therapeuticcompound, or a combination thereof.

In one embodiment of this invention, the term “depth” refers to ameasurement of a scaffold of this invention extending from an imaginaryline resting on the open surface of a repair site to a place beneath thetissue floor at a site of cartilage repair.

For example, based on a site of cartilage repair shaped like acylindrical pit with a single continuous wall and a floor, in oneembodiment a scaffold may be placed so that it extends through thefloor, therefore, the depth of a region of the scaffold is below thefloor, wherein the region penetrates into a bone marrow. This isbeneficial for cartilage repair, since the bone marrow represents asource of mesenehymal stem cells. Moreover, other nutrients, effectorcompounds, or therapeutic compounds, or a combination thereof that maybe found in the tissue milieu at or proximal to a site of repair, maynow be in contact with the scaffold as it penetrates bone and othertissue to reach the bone marrow.

In one embodiment, the depth of a region of a scaffold may be below anytissue surface that lines a site of cartilage repair such that a regionof the scaffold penetrates into a bone marrow.

It will be recognized by one skilled in the art that the depth of otherregions of the scaffold may not be below any tissue surface. Based on asite of cartilage repair shaped like a cylindrical pit, an imaginaryline drawn to rest across the opening of the pit represents the top ofthe pit. In one embodiment, positioning of the scaffold results in theentirety of the scaffold being below the top of the pit and therefore ata depth below the imaginary line across the opening. In one embodiment,positioning of the scaffold results in a portion of the scaffold beingabove the top of the pit and therefore not wholly within a site ofcartilage repair. The benefit of placing a scaffold at a given depth maydepend on the resulting contact the scaffold makes with surroundingtissue, either within the site of cartilage repair or proximal to thesite of cartilage repair.

In one embodiment, the term “angle” refers to a measurement of the arcformed by an imaginary line along the long axis of the scaffold and animaginary plumb line perpendicular to the line resting at the opening ofa site of cartilage repair described above, with the arc progressing ina clockwise direction around this imaginary plumb line. Thus, in oneembodiment a scaffold of this invention may be positioned and confinedat an optimal depth and angle such that the scaffold is parallel to theperpendicular line, and therefore the angle would be 0 degrees. In oneembodiment a scaffold of this invention may be positioned perpendicularto the imaginary plumb line, and therefore the angle would be 90degrees. In one embodiment, the scaffold is positioned and confined atan angle equaling or less than 10 degrees. In one embodiment, thescaffold is positioned and confined at an angle equaling or less than 35degrees. In one embodiment, the scaffold is positioned and confined atan angle equaling or less than 55 degrees. In one embodiment, thescaffold is positioned and confined at an angle equaling or less than 75degrees. In one embodiment, the scaffold is positioned and confined atan angle equaling or less than 95 degrees. In one embodiment, thescaffold is positioned and confined at an angle equaling or less than115 degrees. In one embodiment, the scaffold is positioned and confinedat an angle equaling or less than 125 degrees. In one embodiment, thescaffold is positioned and confined at an angle of less than 145degrees. In one embodiment, the scaffold is positioned and confined atan angle equaling or less than 165 degrees. In one embodiment, thescaffold is positioned and confined at an angle less than 180 degrees.

In some embodiments, multiple scaffolds are inserted to maximally occupya defect site, such that each scaffold material may be inserted at adifferent angle, to accommodate proper insertion into the desired regionwithin a site of cartilage repair. It is to be understood that thereference to angles of positioning above may be with regard to one ormore scaffolds inserted in a particular cartilage defect site.

Contact between exposed surfaces of a scaffold and tissue at or proximalto a site of cartilage repair provides a bioactive surface which, in themethods of use of this invention may induce or enhance cartilage repair.For example, in one embodiment, the exposed surface of a scaffoldprovides a bioactive surface attracting mesenchymal stem cells. Inanother embodiment, the exposed surface provides a place for mesenchymalstem cell attachment, growth, proliferation, or differentiation, or acombination thereof, all processes which induce or enhance cartilagerepair. In addition, the exposed surface of a scaffold may attract bloodvessels. Moreover, tissue at or proximal to a site of cartilage repairmay be a rich source of nutrients, effector compounds, therapeuticcompounds, or a combination thereof, which may be beneficial incartilage repair so that contact between an exposed surface of ascaffold and such tissue induces or enhances cartilage repair.

In one embodiment, the angle of placement of a scaffold is such that thescaffold is in contact with a region of a wall within a site ofcartilage repair. In one embodiment, a scaffold of this invention may bepositioned and confined such that there is maximal contact between thescaffold and tissues at or proximal to a site of cartilage repair. Inone embodiment, a scaffold of this invention may be positioned andconfined such that a region of the scaffold penetrates a bone marrow andthere is maximal contact between the scaffold and tissues at or proximalto a site of cartilage repair. In one embodiment, contact between theexposed surface of the scaffold and the tissue at or proximal to a siteof cartilage repair provides maximal surface area of the scaffold forinteraction with a population of mesenchymal stem cells, blood vessels,effector compounds, or other components of a tissue milieu, or acombination thereof.

A scaffold of this invention may comprise multiple raised portions. Itis possible for different portions of a scaffold to serve differentfunctions. For example, in one embodiment a raised portion of a scaffoldmay penetrate a hone marrow, or a raised portion of a scaffold may holdthe scaffold in place within a site of cartilage repair, or a raisedportion of a scaffold may function as an exposed surface for attraction,growth, proliferation or differentiation of mesenchymal stem cells, or araised portion of a scaffold may function to fit a tool of thisinvention, or any combination thereof.

In one embodiment, 100% of multiple raised portions specificallypositions and confines a coral. In one embodiment, at least 80% ofmultiple raised portions specifically positions and confines a coral. Inone embodiment, at least 60% of multiple raised portions specificallypositions and confines a coral. In one embodiment, at least 40% ofmultiple raised portions specifically positions and confines a coral. Inone embodiment, at least 20% of multiple raised portions specificallypositions and confines a coral. In one embodiment, at least 10% ofmultiple raised portions specifically positions and confines a coral. Inone embodiment, at least 1% of multiple raised portions specificallypositions and confines a coral.

In one embodiment, placing and confining a scaffold of this invention atan optimal depth and angle within a site of cartilage repair providesfor penetration of a portion of the exposed surface of the scaffold,through a bone tissue, resulting in the exposed surface inserting withina bone marrow proximal to a site of cartilage repair.

By optimizing the specific positioning of a scaffold the porouscrystalline structure of a coral scaffolds of this invention, describedbelow, is accessible to beneficial components located within a tissuemilieu. For example, the porous crystalline structure of coral allowsin-growth of blood vessels to create a blood supply for the cartilagethat will infiltrate the scaffold during cartilage repair. Bypenetrating into a bone marrow, mesenchymal stem cells located withinthe bone marrow now have access to the exposed surface of the scaffold.In one embodiment, the region of the scaffold penetrating into a bonemarrow attracts mesenchymal stern cells from the bone marrow andpromotes blood vessel formation to the site of cartilage repair. In oneembodiment, the region of the scaffold penetrating into a bone marrowpromotes adhesion, proliferation, or differentiation or a combinationthereof, of the mesenchymal stem cells attracted to the scaffold.

Thus, it will be apparent to one skilled in the art that the specificpositioning of the scaffold within a site of cartilage repair arrangesthe scaffold of this invention such that the scaffold is most effectivefor cartilage repair.

In one embodiment, “scaffold” refers to a shaped platform used forcartilage repair, wherein the shaped platform provides a site forcartilage regeneration. In one embodiment, the scaffold is a temporaryplatform. In one embodiment, “temporary platform” refers to a naturaldegradation of a coral of this invention that occurs over time duringcartilage repair, wherein the natural degradation of the coral mayresults in a change of scaffold shape over time, a change in scaffoldsize over time.

In one embodiment, the coral is shaped in the form of the tissue to begrown. For example, the coral can be shaped as a piece of cartilaginoustissue, such as a meniscus for a knee or elbow; a joint; an articularsurface of a bone, the rib cage, a hip, a pelvis, an ear, a nose, thebronchial tubes and the intervertebral discs.

This invention provides, in some embodiments, coral scaffolds for use inrepairing cartilage tissue defects associated with physical trauma, orcartilage tissue defects associated with a disease or disorder in asubject.

In one embodiment of this invention, the tam “coral” refers to coralwhich is cut from a single piece of coral. In one embodiment, the coralhas pore-like cavities or interstices.

In one embodiment, the coral scaffold is shaped prior to use in a methodof cartilage repair. In one embodiment, the coral scaffold is shapedconcurrent with a method of cartilage repair, e.g., the coral scaffoldmay be shaped during surgery when the site of repair may be bestobserved, thus optimizing the shape of the scaffold used.

In one embodiment, the scaffolds, methods and/or kits of this inventionemploy use of a coral. In one embodiment, the coral comprise anyspecies, including, inter alia, Porites, Acropora, Millepora, or acombination thereof.

In one embodiment, the coral is from the Porites species. In oneembodiment, the coral is Porites Lutea. In most species, the void tosolid ratios is generally in the range of 0.4 to 0.6, and the void phasecompletely interconnects, forming a highly regular network thatinterpenetrates the solid calcium carbonate phase. In one embodiment,this uniform and interconnecting architecture is particularly useful asa framework in the scaffolds, methods and/or kits of this invention.

In one embodiment, the coral is from the Acropora species. In oneembodiment, the coral is Acropora grandis, which in one embodiment isvery common, fast growing, and easy to grow in culture. Thus, in oneembodiment Acropora samples can be easily collected in sheltered areasof the coral reefs and collection from the coral reefs can be avoided byuse of cultured coral material.

The average skeletal density of Acropora grandis is 2.7 g/ml. Becausethe skeleton of this coral species is dense and strong, it can be easilymachined to a variety of configurations of shaped products or structuresof different sizes, for example by grinding. This material isparticularly suited for use in an implant device, in particular forweight-bearing joints such as knee and hip joints, where strength is anessential property of the implant device. Thus, in one embodiment,Acropora coral is useful as a framework in the scaffolds, methods and/orkits of this invention.

In another embodiment, the coral is from the Millepora species. In oneembodiment, the coral is Millepora dichotoma. In one embodiment, thecoral has a pore size of 150 μm and can be cloned and cultured, makingMillerpora useful as a framework in the scaffolds, methods and/or kitsof this invention.

In another embodiment, the coral is from any one or more of thefollowing species: Favites halicora; Goniastrea regformis; Acanthastreaechinata; Aeanthastrea hempriehi; Acanthastrea ishigakiensis; Acroporaaspera; Acropora austera; Acropora sp. “brown digitate”; Acroporacarduus; Acropora cereals; Acropora chesterfieldensis; Acroporaclathrata; Acropora cophodactyla; Acropora sp. “danai-like”; Acroporadivaricata; Acropora donei; Acropora echinata; Acropora efflorescens;Acropora gemmifera; Acropora globiceps; Acropora granulosa; Acropora cfhempriehi; Acropora kosurini; Acropora cf loisettae; Acroporalongicyathus; Acropora loripes; Acropora cf lutkeni; Acroporapaniculata; Acropora proximalis; Acropora rudis; Acropora selago;Acropora solitaryensis; Acropora cf spicifera as per Veron; Acropora cfspicifera as per Wallace, Acropora tenuis; Acropora valenciennesi;Acropora vaughani; Acropora vermiculata; Astreopora gracilis; Astreoporamyriophthalma; Astreopora randalli; Astreopora suggesta; Australomussarowleyensis; Coscinaraea coilumna; Coscinaraea crassa; Cynarinalacrymalis; Distichopora violacea; Echinophyllia echinata; Echinophylliacf eclzinoporoides; Echinopora gemmacea; Echinopora hirsutissima;Eitphyllia ancora; Euphyllia divisa; Euphyllia yaeyamensis; Faviarotundata; Favia truncatus; Favites acuticollis; Favities pentagona;Fungia granulosa; Fungia klunzingeri; Fungia mollucensis; Galaxeaacrhella; Goniastrea edwardsi; Goniastea minuta; Hydnophora pilosa;Leptoseris explanata; Leptoseris incrustans; Leptoseris mycetoseroides;Leptoseris scabra; Leptoseris yabei; Lithophyllon unduiatum; Lobophylliahemprichii; Merulina scabricula; Millepora dichotoina; Millepora exaesa;Millipora intricata; Millepora murrayensis; Millipora platyphylla;Monastrea curta; Monastrea colemani; Montipora caliculata; Montiporacapitata; Montipora foveolata; Montipora meandrina; Montiporatuberculosa; Montipora cf vietnamensis; Oulophyllia laevis; Oxyporacrassispinosa; Oxypora lacera; Pavona bipartita; Pavona venosa; Pectiniaalcicornis; Pectinia paeonea; Platygyra acuta; Platygyra pini; Platygyrasp “green”; Platygyra verweyi; Podabacia cf lanakensis; Porites annae;Porites cylindrica; Porites evermanni; Porites monticulosa; Psammocoradigitata; Psammocora expianulata; Psammocora haimeana; Psarnmocorasuperlicialis; Sandalolitha dentata; Seriatopora caliendrum;Stylocoeniella armata; Stylocoeniella guentheri; Stylaster sp.; Tubiporamusica; Turbinaria stellulata; or any coral known in the art, or acombination thereof.

In another embodiment, coral for use in the scaffolds, methods and/orkits of this invention may be Madreporaria, Helioporida of the orderCoenothecalia, Tubipora of the order Stolonifera, Millepora of the orderMilleporina, or others known in the art. In some embodiments, coral foruse in the scaffolds, methods and/or kits of this invention may compriseseleractinian coral, including in some embodiments, Goniopora andothers. In some embodiments, coral for use in the scaffolds, methodsand/or kits of this invention may comprise Alveoppora. In someembodiments, coral for use in the scaffolds, methods and/or kits of thisinvention may comprise bamboo corals, including in some embodiments,coral from the family Isididae, genera Keratoisis, Isidella, and others.

In one embodiment, the size of a scaffold may be any size that would beuseful for the purposes of the present invention, as would be known toone skilled in the art. In one embodiment, the scaffold or a portionthereof may be about the size of a site of cartilage repair. In oneembodiment, the scaffold or a portion thereof may be about the size of acartilage defect so that the scaffold may be placed within a site ofcartilage repair. In another embodiment, the scaffold may be larger thanthe size of a cartilage defect. For example, in one embodiment, thescaffold of this invention may be larger than the size of a cartilagedefect, whereby the scaffold may extend to a site of mesenchymal cellavailability. In one embodiment, the scaffold may be smaller than thesize of a cartilage defect.

In sonic embodiments, the scaffold size will be on a millimeter scale,for example, having at least one long axis of about 2-200 mm, or in someembodiments, about 1-18 mm, or in some embodiments, about 0.5 mm-3 mm,or in some embodiments, about 6-12 mm, or in some embodiments, about10-15 mm, or in some embodiments, about 12-40 mm, or in someembodiments, about 30-100 mm, or in some embodiments, about 50-150 mm,or in some embodiments, about 100-200 mm.

In one embodiment, the scaffold may be about the same size as a tissuevoid at a site of tissue repair. This tissue void may be due to acartilage defect, cartilage degeneration or may have been createdartificially during methods of cartilage repair or any combinationthereof. In one embodiment, the tissue void comprises an absence ofcartilage tissue. In one embodiment of this invention, the tissue voidcomprises an absence of cartilage and bone tissue. In one embodiment,the scaffold or a portion thereof may be the size of a cartilage defectsuch that the scaffold may be placed within a site of cartilage repairto enhance cartilage formation at the site of cartilage repair. Inanother embodiment, the scaffold may be larger than the size of acartilage defect so that the scaffold may reach to a site of mesenchymalstem cell availability.

In one embodiment of this invention, “about” refers to a quality whereinthe means to satisfy a specific need is met, e.g., the size may belargely but not wholly that which is specified but it meets the specificneed of cartilage repair at a site of cartilage repair. In oneembodiment, “about” refers to being closely or approximate to, but notexactly. A small margin of error is present. This margin of error wouldnot exceed plus or minus the same integer value. For instance, about 0.1micrometers would mean no lower than 0 but no higher than 0.2.

In one embodiment, the term “void” refers to a space not occupied. Inthe instant invention, for example, in one embodiment, avoid may be aspace in a coral naturally not occupied. In one embodiment, a void maybe a space not occupied at a site of repair. In one embodiment, ovoidmay be a space not occupied within a scaffold of the current invention.

In one embodiment, a coral for use in a scaffold of this inventioncomprises an average pore size appropriate for seeding with precursorcells. In one embodiment, the average pore size of a coral is 1 μm-1 mm.In one embodiment, the average pore size of a coral is 30-180 μm. In oneembodiment, the average pore size of a coral is 50-500 μm. In oneembodiment, the average pore size of a coral is 150-220 μm. In oneembodiment, the average pore size of a coral is 250-1000 μm.

Processing of coral for use in scaffolds, methods of use, and kitsthereof, may be as described in PCT International Application No.PCT/IL08/001511, which is incorporated by reference as if fully setforth herein. Further details in this respect are provided hereinunder.

In one embodiment, coral is purified from organic residues, washed,bleached, frozen, dried, sterilized or a combination thereof prior toseeding with precursor cells.

In one embodiment, scaffolds and scaffolds for use in the methods andkits of this invention are produced according to a process comprisingwashing naturally occurring coral sand with water to desalinate it, thendisinfecting and drying the desalinated coral sand at temperatures ofabout 80° to about 150° C., preferably 90° to 120° C., and grinding thedisinfected and dried coral into small particles, which in oneembodiment comprise particles of 1-10 μm. In another embodiment, coralis ground into particles of 1-5, 1-20, 1-50, 1-100, 5-10, 10-15, 15-20,10-50, 10-100, 20-100, 50-100, 80-150, 100-200, 100-350 or 150-500 μm.

Coral scaffolds of this invention comprise at least a first portion ofan exposed surface raised with respect to at least a second portion ofthe exposed surface in the coral (FIGS. 1-3). The exposed raised surfacemay serve multiple functions with respect to methods of use of thisinvention and kits thereof. In one embodiment, a raised portionpositions and confines a scaffold of this invention. In one embodiment,a raised portion penetrates through bone to insert within a bone marrow,thereby reaching a source of mesenchymal stem cells. In one embodiment,the exposed surfaces of raised and non-raised portions of the scaffoldprovide a site for the attraction, growth, proliferation ordifferentiation, or a combination thereof for mesenchymal stem cells.

In one embodiment of this invention, the term “portion” refers to alimited part of a whole.

In one embodiment, the term “portion of an exposed surface” refers to alimited part of a Whole exposed surface. For example, in one embodimenta portion of an exposed surface comprises less than 100% of the exposedsurface. In one embodiment a portion of an exposed surface comprisesless than 90% of the exposed surface. In one embodiment a portion of anexposed surface comprises less than 80% of the exposed surface. In oneembodiment a portion of an exposed surface comprises less than 70% ofthe exposed surface. In one embodiment a portion of an exposed surfacecomprises less than 60% of the exposed surface. In one embodiment aportion of an exposed surface comprises less than 50% of the exposedsurface. In one embodiment a portion of an exposed surface comprisesless than 40% of the exposed surface. In one embodiment a portion of anexposed surface comprises less than 30% of the exposed surface. In oneembodiment a portion of an exposed surface comprises less than 20% ofthe exposed surface. In one embodiment a portion of an exposed surfacecomprises less than 10% of the exposed surface. In one embodiment aportion of an exposed surface comprises less than 1% of the exposedsurface.

In one embodiment of this invention, the term “surface” refers to anexterior or upper boundary of an object.

In one embodiment of this invention, the term “exposed” refers to beingopen to the surrounding environment such that contact may occur betweena coral scaffold of this invention and the surrounding environment. Forexample, in one embodiment the coral of this invention may be in contactwith a surrounding environment comprising a site of cartilage repair, atissue milieu, or a cell culture milieu.

In one embodiment, the term “exposed surface” refers to a surface of acoral being accessible/open/available, for instance to a site ofcartilage repair. In one embodiment, the exposed surface may comprise apolymer coating, wherein the coating is accessible/open/available to asite of tissue repair. In one embodiment, an exposed surface of thisinvention is accessible to mesenchymal stem cells or to adjacent tissuesthat participate in the cartilage repair process, such as nativecartilage and bone cells, such as chondrocytes, osteoblasts,osteoclasts, etc. In one embodiment, an exposed surface of thisinvention has access to effector compounds beneficial for cartilagerepair. In one embodiment, an exposed surface of this invention mayappear to be internal to the scaffold. In one embodiment, the term“internal” refers to those surfaces not easily seen from a particularexternal perspective; such surfaces comprise exposed surfaces withinpore-like cavities or interstices of a coral and exposed surfaces ofhollow spaces created within a coral, e.g., the internal exposedsections shown in the longitudinal cross-sections in FIG. 4, or thevoids in FIGS. 1-3 comprise an exposed surface.

In one embodiment, the contact between the coral of this invention andthe environment comprises the coral touching the environment. Forexample, in one embodiment the coral of this invention may touch thesurface of a site of cartilage repair.

In one embodiment, methods of this invention may involve placement of acoral on a surface at site of cartilage repair. In one embodiment,methods of this invention may involve components of a tissue milieu at asite of coral repair migrating to an exposed surface of a coral andcontact between the coral of this invention would be made thus with theenvironment.

In one embodiment, methods of this invention may involve implanting ascaffold so that raised exposed surfaces of the scaffold forcefullycontact the tissue at or adjacent to a site of cartilage repair. In thisway, the exposed surface of coral now proximal to a site of cartilagerepair is proximal to an environment comprising cartilage tissue, bonetissue, bone marrow tissue, mesenchymal stein cells, nutrients, bloodvessels or other effector compounds, or a combination thereof, which maybe beneficial to cartilage repair.

In one embodiment, methods of this invention which provide for thecontact of coral with the surrounding environment results in migrationof mesenchymal cells, blood vessels, nutrients, therapeutic compounds oreffector compounds, or a combination thereof beneficial to cartilagerepair. In one embodiment, the contact of coral with mesenchymal stemcells occurs in an in vitro culture.

In one embodiment of this invention, the phrase “at least a firstportion of an exposed surface raised with respect to at least a secondportion of the exposed surface” refers to the first portion of anexposed surface projecting from a coral of this invention such that thefirst portion of the exposed surface comprises an elevation above atleast a second portion of the exposed surface in the coral. It will beapparent to one skilled in the art that the first portion of an exposedsurface raised with respect to at least a second portion of the exposedsurface provides for increased overall surface area of a coral scaffoldof this invention and provides for at least a region which specificallypositions and confines said coral at an optimal depth and angle within asite of cartilage repair. In one embodiment, scaffolds of this inventionare shaped to maximize exposed surface area.

In one embodiment of this invention, the exposed surface comprisesmultiple raised portions, with respect to other portions on saidsurface, e.g., the multiple raised portions on the exposed surface shownin FIGS. 1A-1E, region 1-20, or FIGS. 2A-2D, region 2-20 or FIGS. 3A and3C, region 3-20. In one embodiment, the multiple raised portions providefor increased exposed surface area of a coral scaffold. In oneembodiment, the multiple raised portions may each provide at least aregion which specifically positions and confines said coral at anoptimal depth and angle within a site of cartilage repair. In oneembodiment, a single multiple raised portion provides at least a regionwhich specifically positions and confines said coral at an optimal depthand angle within a site of cartilage repair. In one embodiment, at least10% of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, at least 20%of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, at least 30%of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, at least 50%of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, at least 70%of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, at least 90%of the multiple raised portions provide at least a region whichspecifically positions and confines said coral at an optimal depth andangle within a site of cartilage repair. In one embodiment, 100% of themultiple raised portions provide at least a region which specificallypositions and confines said coral at an optimal depth and angle within asite of cartilage repair.

In some embodiments, by adapting the dimensions, numbers, or placement,or a combination thereof, of the raised portions of a scaffold, thescaffold can be designed for use in methods and/or kits of thisinvention to induce or enhance cartilage repair, at sites of cartilagerepair which may be vastly different from each other based on size,location, e of repair needed, type of defect present, or distance fromthe site to a bone marrow, or a combination thereof.

In one embodiment of this invention, the phrases “long axis of thescaffold” and longitudinal axis of the scaffold” are usedinterchangeably and refer to a line extending parallel to the scaffoldlengthwise. The term “lengthwise” refers the direction of the length ofa scaffold. It may be that an original geometric shape has been cut toproduce a horizontal section of the original scaffold. In such instanceslengthwise should be viewed as being the original direction of lengthalong a scaffold.

In one embodiment, first multiple raised portions are positioned at aperiodic distance with respect to each other on the surface. In oneembodiment of this invention, the phrase “periodic distance” refers to adistance between multiple raised portions which comprises occurring orrecurring regular intervals. In one embodiment, the periodic distance isthe distance between facing junctions of one multiple raised portion onthe surface with a directly adjacent multiple raised portion. In oneembodiment, the periodic distance is the distance between the centrallong axis of one multiple raised portion on the surface with the centrallong axis of a directly adjacent multiple raised portion.

In one embodiment, first multiple raised portions are positioned at anaperiodic distance with respect to each other on the surface. In oneembodiment of this invention, the phrase “aperiodic distance” refers toa distance between multiple raised portions which comprises irregularoccurrences. In one embodiment, the aperiodic distance is the distancebetween facing junctions of one multiple raised portion on the surfacewith a directly adjacent multiple raised portion. In one embodiment, theaperiodic distance is the distance between a central long axis of onemultiple raised portion on the surface with the central long axis of adirectly adjacent multiple raised portion.

In one embodiment of this invention, the first multiple raised portionsare of about equal height with respect to each other on the surface. Inone embodiment, height comprises the furthest distance from the surfaceof a scaffold to the upper limit of a raised portion on the surface ofthe scaffold.

In one embodiment of this invention, the first multiple raised portionsare of about unequal height with respect to each other on the surface.

In one embodiment of this invention, the first multiple raised portionsare of about equal width with respect to each other on the surface. Inone embodiment, width comprises a measurement along a horizontal line ofthe raised portion positioned at right angle to the long axis of theraised portion. In one embodiment of this invention, the first multipleraised portions have about equal widths for all horizontal lines withrespect to each other on the surface.

In one embodiment, a multiple raised portion may have equal widths alongany horizontal line of the raised portion with itself. In oneembodiment, a multiple raised portion may have unequal widths along anyhorizontal line of the raised portion with itself.

In one embodiment of this invention, the first multiple raised portionsare of unequal width with respect to each other on the surface. In oneembodiment of this invention, the first multiple raised portions haveunequal widths for all horizontal lines with respect to each other onthe surface.

In one embodiment of this invention, the first multiple raised portionsare positioned within a discrete region of the surface, wherein thediscrete region does not cover 100% of the surface. In one embodiment ofthis invention, the first multiple raised portions are positioned withina discrete region of the surface, wherein the discrete region covers50-100% of the surface. In one embodiment of this invention, the firstmultiple raised portions are positioned within a discrete region of thesurface, wherein the discrete region covers less than 50% of thesurface.

In one embodiment, a coral of this invention comprises a solidthroughout a scaffold. One skilled in the art will recognize that solidcoral of this invention still comprises pore-like cavities and/orinterstices.

In one embodiment, a coral of this invention comprises a hollow along aCartesian coordinate axis of a scaffold. In one embodiment, the hollowis along a long axis of a scaffold of this invention. In one embodiment,the term “hollow” refers to a cavity within a coral that results in acavity within a scaffold of this invention. In one embodiment, thehollow comprises at least a single opening in the coral such that thecavity is exposed to the external environment. For example, FIGS. 1A-1Eand 2A-2D show embodiments of scaffolds used in methods of thisinvention, wherein a series of hollows are present along the long axisof the representative scaffolds. In one embodiment, the hollow providesadditional exposed surface area for a scaffold of this invention.

In some embodiments, such hollow or hollows may be constructed by anymechanical means, whereby the hollow/hollows is introduced. In someembodiments, such hollow creation may be by means of controlled drillinginward from a scaffold surface to a desired depth. In some embodiments,the specific creation of such hollows allows for ingrowth into thescaffold of appropriate cells involved in cartilage and/or bone repair,growth of blood vessels and other elements necessary for repair. In someembodiments, the hollows are specifically constructed within thescaffolds of the invention to be of a depth sufficient to span thecartilage area in which the scaffold is inserted to stimulate/enhancerepair, and in some embodiments, such depth will not be sufficient toreach the bone.

In some embodiments, the scaffolds of this invention will comprisemultiple hollows, which may be in any orientation, or in someembodiments, the scaffolds of this invention will comprise a network ofhollows within scaffolds, or in some embodiments, multiple scaffolds areimplanted into a repair site, wherein hollows of the scaffolds arealigned to form a network of hollows throughout the implanted scaffolds.

The exposed surface area of a scaffold of this invention provides alocation for mesenchymal stem cell attachment, growth, proliferation ordifferentiation, or a combination thereof and a location for bloodvessels formation. Therefore, the surface area of a scaffold of thisinvention ultimately provides a beneficial location for regeneration ofcartilage tissue. Thus, it is advantageous to increase the surface areaof a scaffold of this invention, for use in methods and kits of thisinvention. In one embodiment of this invention, a scaffold comprises ahollow, wherein the presence of the hollow increases the exposed surfacearea of a scaffold compared to an analogous scaffold without a hollow.In one embodiment, a scaffold comprises a coral cut with a hollow spaceto maximize surface area of the coral.

In one embodiment of this invention, the coral comprises a polymercoatis embodiment, a polymer coating strengthens the scaffold and/orenhance cartilage repair.

In one embodiment of this invention, a polymer coating is permeable. Inone embodiment, the permeable polymer coating comprises a special porousmembrane. In one embodiment, the term “permeable” refers to having poresand openings. In one embodiment, the permeable polymer coating of thisinvention has pores and openings which allow entry of nutrients, atherapeutic compound, a cell population, a chelator, or a combinationthereof. In one embodiment, the permeable polymer coating of thisinvention has pores and openings which allow exit/release of nutrients,a therapeutic compound, a cell population, a chelator, or a combinationthereof and/or blood vessels formation.

In one embodiment, a polymer coating of this invention is discontinuous.In one embodiment, a region or a plurality of sub-regions of the coralof this invention comprise an absence of polymer coating, allowingdirect contact between the coral and the environment.

In one embodiment, a polymer coating of this invention may be a film,may take on the form of discontinuous particles and/or aggregates or acombination thereof. Example 2 and FIGS. 8A and 8B herein describeherein describes the preparation of an embodiment of a scaffold of thisinvention incorporating hyaluronic acid particles, representing anembodiment of this invention.

In one embodiment, a polymer coating of this invention comprises anatural polymer comprising, collagen, elastin, silk, hyaluronic acid,chytosan, and any combinations thereof.

In one embodiment, the polymer comprises synthetically modified naturalpolymers, and may include cellulose derivatives such as alkylcelluloses, hydroxyalkyl celluloses, cellulose ethers, cellulose esters,nitrocelluloses, and chitosan. Examples of suitable cellulosederivatives include methyl cellulose, ethyl cellulose, hydroxypropylcellulose, hydroxypropyl methyl cellulose, hydroxybutyl methylcellulose, cellulose acetate, cellulose propionate, cellulose acetatebutyrate, cellulose acetate phthalate, carboxymethyl cellulose,cellulose triacetate and cellulose sulfate sodium salt.

In one embodiment, of this invention, a polymer comprises a syntheticbiodegradable polymer. In one embodiment of this invention, a syntheticbiodegradable polymer comprises alpha-hydroxy acids includingpoly-lactic acid, polyglycolic acid, enantioners thereof, co-polymersthereof, polyorthoesters, and combinations thereof.

In one embodiment, a polymer of this invention comprises apoly(cianoacrylate), poly(alkyl-cianoacrylate), poly(ketal),poly(caprolactone), poly(acetal), poly(α-hydroxy-ester),poly(α-hydroxy-ester), poly(hydroxyl-alkanoate),poly(propylene-fumarate), poly (imino-carbonate), poly(ester),poly(ethers), poly(carbonates), poly(amide), poly(siloxane),poly(silane), poly(sulfide), poly(imides), poly(urea),poly(amide-enamine), poly(organic acid), poly(electrolytes),poly(p-dioxanone), poly(olefin), poloxamer, inorganic or organometallicpolymers, elastomer, or any of their derivatives, or a copolymerobtained by a combination thereof.

In one embodiment, a polymer of this invention comprisespoly(D,L-lactide-co-glycolide) (PLGA). In another embodiment, thepolymer comprises poly(D,L-lactide) (PLA). In another embodiment, thepolymer comprises poly(D,L- glycolide) (PGA). In one embodiment, thepolymer comprises a glycosaminoglycan.

In one embodiment, the polymer comprises synthetic degradable polymers,which may include, but are not limited to polyhydroxy acids, such aspoly(lactide)s, poly(glycolide)s and copolymers thereof; polyethyleneterephthalate); poly(hydroxybutyric acid); poly(hydroxyvaleric acid);poly[lactide-co-(ε-caprolactone)]; poly[glycolide-co(ε-caprolactone)];poly(carbonate)s, poly (pseudo amino acids); poly(amino acids);poly(hydroxyalkanoate)s; poly(anhydrides); poly(ortho ester)s; andblends and copolymers thereof.

In one embodiment of this invention, a polymer comprises proteins suchas zein, modified zein, casein, gelatin, gluten, serum albumin,collagen, actin, α-fetoprotein, globulin, macroglobulin, cohesin,laminin, fibronectin, fibrinogen, osteocalcin, osteopontin,osteoprotegerin, or others, as will be appreciated by one skilled in theart. In another embodiment, a polymer may comprise cyclic sugars,cyclodextrins, synthetic derivatives of cyclodextrins, glycolipids,glycosaminoglycans, oligosaccharide, polysaccharides such as alginate,carrageenan (χ, λ, μ, κ), chitosane, celluloses, condroitin sulfate,curdian, dextrans, elsinan, furcellran, galactomannan, gellan, glycogen,arabic gum, hemicellulose, inulin, karaya gum, levan, pectin, pollulan,pullulane, prophyran, scleroglucan, starch, tragacanth gum, welan,xanthan, xylan, xyloglucan, hyaluronic acid, chitin, or apoly(3-hydroxyalkanoate)s, such as poly(β-hydroxybutyrate),poly(3-hydroxyoctanoate) or poly(3-hydroxyfatty acids), or anycombination thereof.

In one embodiment, the polymer comprises a bioerodible polymer such aspoly(lactide-co-glycolide)s, poly(anhydride)s, and poly(orthoester)s,which have carboxylic groups exposed on the external surface as thesmooth surface of the polymer erodes, which may also be used. In oneembodiment, the polymer contains labile bonds, such as polyanhydridesand polyesters.

In one embodiment, a polymer may comprise chemical derivatives thereof(substitutions, additions, and elimination of chemical groups, forexample, alkyl, alkylene, hydroxylations, oxidations, and othermodifications routinely made by those skilled in the art), blends of,e.g. proteins or carbohydrates alone or in combination with syntheticpolymers.

In one embodiment of this invention, the polymer is biodegradable. Inone embodiment, the term “biodegradable” or grammatical forms thereof,refers to a material of this invention, which is degraded in thebiological environment of the subject in which it is found. In oneembodiment, the biodegradable material undergoes degradation, duringwhich, acidic products, or in another embodiment, basic products arereleased. In one embodiment, bio-degradation involves the degradation ofa material into its component subunits, via, for example, digestion, bya biochemical process. In one embodiment, biodegradation may involvecleavage of bonds (whether covalent or otherwise), for example in apolymer backbone of this invention. In another embodiment,biodegradation may involve cleavage of a bond (whether covalent orotherwise) internal to a side-chain or one that connects a side chainto, for example a polymer backbone.

In one embodiment, a coral of this invention is covalently associatedwith the polymer coating via the use of a cross-linking agent. In oneembodiment, the phrase “cross-linking agent” refers to an agent whichfacilitates the formation of a covalent bond between 2 atoms. In oneembodiment, the cross-liking agent is a zero-length cross-linking agent.

In one embodiment, the cross-linking agent is (1 ethyl 3-(3dimethylarninopropyl)carbodiimide (EDAC), N-Sulfohydroxy succinamide (SulfoNHS), 5-iodopyrimidines, N-carbalkoxydihydroquinolines,pyrroloquinolinequinones, or a combination thereof.

In one embodiment, the cross-linking agent is a homobifimetionalcross-linker, such as, for example, a N-hydroxysuccinimide ester (e.g.disuccinimidyl suberate or dithiobis(succinimidylpropionate),homobifunctional imidoester (e.g. dimethyladipiraidate or dimethylpimelimidate), sulfhydryl-reactive crosslinker (e.g.1,4-di-[3′-(2′-pyridyldithio)propionarnido]butane), difluorobenzenederivative (e.g. 1,5-difluoro-2,4-dinitrobenzene), aldehyde (e.g.formaldehyde, glutaraldehyde), bis-epoxide (e.g. 1,4-butanedioldiglycidyl ether), hydrazide (e.g. adipic acid dihydrazide),bis-diazonium derivative (e.g. o-tolidine), bis-alkylhalide, or acombination thererof.

In one embodiment, the cross-linking agent is a heterobifunctionalcross-linker, such as, for example, an amine-reactive andsulfhydryl-reactive crosslinker (e.g. N-succinimidyl3-(2-pyrklyldithio)propionate, a carbonyl-reactive andsulfhydryl-reactive crosslinker (e.g. 4-(4-N-maleimidopheny)butyric acidhydrazide), or a combination thereof.

In some embodiments, the cross-linking agent is a trifunctionalcross-linkers, such as, for example,4-azido-2-nitrophenyibiocytin-4-nitrophenyl ester,sulfosuccinimidyl-2-[6-biotinamido]-2-(p-azidobenzamido)hexanoamido]ethyl-1,3′-dithiopropionate(sulfo-SBED), or a combination thereof.

In another embodiment, the cross-linking agent is an enzyme. In oneembodiment of this invention, the cross-linking agent comprises atransglutaminase, a peroxidase, a xanthine oxidase, a polymerase, or aligase, or a combination thereof.

The choice of concentration of the cross-linking agent utilized foractivity will vary, as a function of the volume, agent and polymerchosen, in a given application, as will be appreciated by one skilled inthe art.

In one embodiment, the association of a coral of this invention with apolymer coating of this invention comprises a physical and/or mechanicalassociation. For example, in one embodiment, a physical and/ormechanical association may comprise imbibing of any means, air drying,using a cross-linking agent, applying of heat, applying vacuum, applyinglyophilizing methods, applying freezing, applying centrifuge, applyingmechanical forces or any combination thereof, to promote the physicaland/or mechanical association between a coral and a polymer coating asdescribed herein.

It will be apparent to one skilled in the art that the physical and/ormechanical and/or chemical properties of a polymer coating andcomponents thereof may influence methods of use of this invention andkits thereof, for inducing or enhancing cartilage repair.

In one embodiment, the polymer coating of this invention has a thicknessof between 0.01 μm and 2.0 μm. In one embodiment, the polymer coatinghas a thickness of about 1.0 μm. In one embodiment, the polymer coatingof this invention has a thickness of between 10 μm and 50 μm. In oneembodiment, the polymer coating has a thickness of about 10-25, or about15-30, or about 25-50 μm. In one embodiment, the polymer coating has athickness of about 50-80, or about 60-90, or about 80-120 μm. In oneembodiment, the polymer coating has a thickness of about 100-150, orabout 130-200, or about 150-250 μm. In one embodiment, the polymercoating has a thickness of about 200-350, or about 300-600, or about450-1000 μm. In some embodiments, multiple scaffolds comprising polymercoatings are implated into a repair site, wherein the coating thicknessof a first scaffold may vary as compared to a coating thickness of asecond scaffold, implanted in the repair site. Variations in the coatingthickness may reflect the range described herein.

In one embodiment, the thickness of the polymer coating influencesphysical characteristics of a scaffold of this invention. For example,the thickness of a polymer coasting may influence elasticity, tensilestrength, adhesiveness, or retentiveness, or any combination thereof ofa scaffold of this invention. In one embodiment, a polymer coatingincreases the elasticity of a scaffold of this invention. In oneembodiment, a polymer coating increases the tensile strength of ascaffold of this invention. In one embodiment, the adhesiveness of apolymer coating relates to adhesion of mesencymal stem cells, bloodvessels, tissue at a site of cartilage repair, cartilage tissue, or bonetissue, or a combination thereof. In one embodiment, a polymer coatingdecreases the adhesiveness of a scaffold of this invention. In oneembodiment, a polymer coating increases the adhesiveness of a scaffoldof this invention. One skilled in the art will recognize that a polymercoating may increase adhesiveness for an item while decreasingadhesiveness for another item. For example, in one embodiment, thepolymer coating increases adhesiveness for a mesenchymal stem cell anddecreases adhesiveness of an infective agent. In one embodiment, theretentiveness of a polymer coating relates to retention of a cellpopulation. In one embodiment, the cell population retained within apolymer coating is a mesenchymal stem cell population. In oneembodiment, the cell population retained within a polymer coating is achondrocytes population. In one embodiment, the cell population retainedwithin a polymer coating is an osteoblasts population. In oneembodiment, the retentiveness of a polymer coating relates to retentionof effector compounds.

In one embodiment, the thickness of the polymer coating influencesproliferation and/or differentiation of mesenchymal stem cells. In oneembodiment, the thickness of a polymer coating is selected to increaseadhesion, proliferation, or differentiation, or a combination thereof,of mesenchymal stein cells with a scaffold of this invention duringmethods of use of the instant invention.

In one embodiment of this invention, the mesenchymal stem cells used ina scaffold, methods of use or kits thereof, are transformed.

In one embodiment, a polymer coating of this invention comprises aneffector compound. In one embodiment, the effector compound is applieddirectly to a polymer coating of the scaffold of this invention. In oneembodiment, the effector compound comprises a component of a kit of thisinvention for use for incorporation into a scaffold of this invention asherein described. In one embodiment, the effector compound is applieddirectly to a polymer coating of this invention, without being dispersedin any solvent.

In one embodiment of this invention, the polymer coating comprises aneffector compound comprising a cytokine, a bone morphogenetic protein(BMP), a chelator, a cell population, a therapeutic compound, or anantibiotic, or any combination thereof.

In one embodiment, effector compounds for use in a scaffold and/or a kitof this invention and/or a method of this invention may comprise,inter-alia cytokine, a bone morphogenetic protein (BMP), a chelator, acell population, a therapeutic compound, or an antibiotic, or anycombination thereof.

In one embodiment, the phrase “a cell population” refers to atransfected cell population, a transduced cell population, a transformedcell population, or a cell population isolated from a subject, or acombination thereof. In some embodiments, transfected, transduced ortransformed cells, may be incorporated into a polymer coat, a coral,coral particles or a scaffold of this invention, or a combinationthereof.

In one embodiment, transfected, transduced or transformed cells, may beincorporated into a polymer coating, a coral, coral particles, ascaffold, or materials of this invention, so that engineered cells maycomprise the polymer coating, coral, coral particles, scaffold, ormaterials of this invention.

In one embodiment, a cell population of this invention comprisesmesenchymal stem cells. In one embodiment, the mesenchymal stem cellsare transformed. In one embodiment, a cell population comprises cellsbeneficial in cartilage repair.

In one embodiment, the coral is seeded with a precursor cell. In oneembodiment, the precursor cell is a mesenchymal stem cell. In otherembodiments, the cell may be a mesenchymal cell; chondrocyte;fibrochondrocyte; osteocyte; osteoblast; osteoclast; synoviocyte; bonemarrow cell; stromal cell; stem cell; embryonic stein cell; precursorcell, derived from adipose tissue; peripheral blood progenitor cell;stem cell isolated from adult tissue; genetically transformed cell; or acombination thereof. In another embodiment, a precursor cell may referto a combination of chondrocytes and other cells; a combination ofosteocytes and other cells; a combination of synoviocytes and othercells; a combination of bone marrow cells and other cells; a combinationof mesenchymal cells and other cells; a combination of stromal cells andother cells; a combination of stem cells and other cells; a combinationof embryonic stem cells and other cells; a combination of precursorcells isolated from adult tissue and other cells; a combination ofperipheral blood progenitor cells and other cells; a combination of stemcells isolated from adult tissue and other cells; and a combination ofgenetically transformed cells and other cells. In one embodiment of thepresent invention, the precursor cells for use in the method of thepresent invention are prepared from an organ tissue of the recipientmammal (i.e. autologous), or a syngeneic mammal. In another embodiment,allogeneic and xenogeneic precursor cells may be utilized.

In one embodiment of this invention, the phrase “a therapeutic compound”refers to a peptide, a protein or a nucleic acid, or a combinationthereof. In another embodiment, the therapeutic compound is anantibacterial, antiviral, antifungal or antiparasitic compound. Inanother embodiment, the therapeutic compound has cytotoxic oranti-cancer activity. In another embodiment, the therapeutic compound isan enzyme, a receptor, a channel protein, a hormone, a cytokine or agrowth factor. In another embodiment, the therapeutic compound isimmunostimulatory. In another embodiment, the therapeutic compoundinhibits inflammatory or immune responses. In one embodiment, thetherapeutic compound comprises a pro-angiogenic factor.

In one embodiment, the phrase “a therapeutic compound”, refers to amolecule, which when provided to a subject in need, provides abeneficial effect. In some cases, the molecule is therapeutic in that itfunctions to replace an absence or diminished presence of such amolecule in a subject. In one embodiment, the molecule is a nucleic acidcoding for the expression of a protein is absent, such as in cases of anendogenous null mutant being compensated for by expression of theforeign protein. In other embodiments, the endogenous protein ismutated, and produces a non-functional protein, compensated for by theexpression of a heterologous functional protein. In other embodiments,expression of a heterologous protein is additive to low endogenouslevels, resulting in cumulative enhanced expression of a given protein.In other embodiments, the molecule stimulates a signaling cascade thatprovides for expression, or secretion, or others of a critical elementfor cellular or host functioning.

In another embodiment, the therapeutic compound may be natural ornon-natural insulins, amylases, proteases, lipases, kinases,phosphatases, glycosyl transferases, trypsinogen, ehymotrypsinogen,carboxypeptidases, hormones, ribonucleases, deoxyribonucleases,triacylglycerol lipase, phospholipase A2, elastases, amylases, bloodclotting factors. UDP glucuronyl transferases, ornithinetranscarbamoylases, cytochrome p450 enzymes, adenosine dearninases,serum thymic factors, thymic humoral factors, thymopoietins, growthhormones, somatomedins, costimulatory factors, antibodies, colonystimulating factors, erythropoietin, epidermal growth factors, hepaticerythropoietic factors (hepatopoietin), liver-cell growth factors,interleukins, interferons, negative growth factors, fibroblast growthfactors, transforming growth factors of the a family, transforminggrowth factors of the β family, gastrins, secretins, cholecystokirins,somatostatins, serotonins, substance P, transcription factors orcombinations thereof.

In one embodiment, a chelator of this invention comprises a Ca2+chelator. In one embodiment, the calcium chelator is EDTA. In oneembodiment, the chelator may comprise: ethylenediamine-N,N,N′,N′-tetaacetic acid (EDTA),N,N-bis(2-aminophenylethyleneglycol)ethylenediamine-N,N,N′N′-tetraaceticacid (BAPTA), N,N-bis(2-hydroxyethyl) glycine (Bicinc),trans-1,2-diaminocyclohexane-ethylenediamine-N,N,N′,N′-tetraacetic acid(CyDTA),1,3-diamino-2-hydroxypropane-ethylenediamine-N,N,N′,N′-tetraacetic acid(DPTA-OH), diethylenetriarnine-N,N,N′,N″,N″-pentaacetic acid (DPTA),ethylenediamine-N,N′-dipropionic acid dihydrochloride (EDDP),ethylenediamine-N,N′-bis(methylenephosphonic acid) hemihydrate (EDDPO),N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (EDTA-OH),ethylenediamine-N,N,N′,N′-tetralds (methylenephosphonic acid) (EDTPO),O,O′-bis(2-aminoethyl) ethyleneglycol tetraacetic acid (EGTA),N,N′-bis(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid (HBED),1,6-hexamethylenediamine-N,N,N′,N′-tetaacetic acid (HDTA),N-(2-hydroxyethyl)iminodiacetic acid (HIDA), iminodiacetic acid (IDA),1,2-diaminopropane-N,N,N′,N′-tetraacetic acid (methyl-EDTA),nitrilotriacetic acid (NTA), nitrilotripropionic acid (NTP),nitilotris(methylenephosphonic acid) trisodium salt (NTPO),N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylethenediamine (TPEN), andtriethylenetetramine-N,N,N′,N″,N″-hexaacetic acid (TTHA), rhod-2, DMSA,FLUO 3, FURA 2, INDO 1, QUIN 2, or other chelators known in the art, ora combination thereof.

In one embodiment, the effector compound comprises, an anti-helminth, anantihistamine, an immunomodulatory, an anticoagulant, a surfactant, abronchodilator, an antibody, a beta-adrenergic receptor inhibitor, acalcium channel blocker, an ace inhibitor, a growth factor, a hormone, aDNA, an siRNA, or a vector or any combination thereof.

In one embodiment, the phrase “effector compound” refers to any agent orcompound, which has a specific purpose or application which is useful inthe treatment, prevention, inhibition, suppression, delay or reductionof incidence of infection, a disease, a disorder, or a condition, whenapplied to the scaffolds, kits and/or methods of this invention. Aneffector compound of this invention, in one embodiment, will produce adesired effect which is exclusive to the ability to image the compound.In some embodiments, the effector compound may be useful in imaging asite at which the compound is present, however, such ability issecondary to the purpose or choice of use of the compound.

In one embodiment of this invention, term “effector compound” is to beunderstood to include the terms “drug” and “agent”, as well, whenreferred to herein, and represents a molecule whose incorporation withinthe scaffold and/or kits of this invention, or whose use thereof, isdesired. In one embodiment, the agent is incorporated directly within ascaffold, and/or kit of this invention. In another embodiment, the agentis incorporated within a scaffold and/or kit of this invention, eitherby physical interaction with a polymer coating, a coral, or coralparticles of this invention, and/or a kit of this invention, orassociation thereto.

In one embodiment, compounds for use in a scaffold and/or a kit of thisinvention and/or a method of this invention may comprise, inter-alia, anantibody or antibody fragment, a peptide, an oligonucleotide, a ligandfor a biological target, an immunoconjugate, a chemomimetic functionalgroup, a glycolipid, a labelling agent, an enzyme, a metal ion chelate,an enzyme cofactor, a cytotoxic compound, a bactericidal compound, abacteriostatic compound, a fungicidal compound, a fungistatic compound,a chemotherapeutic, a growth factor, a hormone, a cytokine, a toxin, aprodrug, an antimetabolite, a microtubule inhibitor, a radioactivematerial, or a targeting moiety, or any combination thereof.

In one embodiment, the scaffolds and/or kits of this invention and/ormethods of this invention comprise or make use of an oligonucleotide, anucleic acid, or a vector. In some embodiments, the term“oligonucleotide” is interchangeable with the term “nucleic acid”, andmay refer to a molecule, which may include, but is not limited to,prokaryotic sequences, eukaryotic mRNA, cDNA from eukaryotic mRNA,genomic DNA sequences from eukaryotic (e.g., mammalian) DNA, and evensynthetic DNA sequences. The term also refers to sequences that includeany of the known base analogs of DNA and RNA.

The scaffolds and/or kits of this invention and/or methods of use ofthis invention may comprise nucleic acids, in one embodiment, or inanother embodiment, the scaffolds and/or kits of this invention and/ormethods of use of this invention may include delivery of the same, as apart of a particular vector. In one embodiment, polynucleotide segmentsencoding sequences of interest can be ligated into commerciallyavailable expression vector systems suitable fortransducing/transforming mammalian cells and for directing theexpression of recombinant products within the transduced cells. It willbe appreciated that such commercially available vector systems caneasily be modified via commonly used recombinant techniques in order toreplace, duplicate or mutate existing promoter or enhancer sequencesand/or introduce any additional polynucleotide sequences such as forexample, sequences encoding additional selection markers or sequencesencoding reporter polypeptides.

In one embodiment, the scaffolds and/or kits of this invention and/ormethods of this invention comprise or make use of a cell population. Inone embodiment, the cell population is a mesenchymal stem cellpopulation. In one embodiment, the mesenchymal stem cell populationcomprises a transformed mesenchymal stem cell population. In oneembodiment, the cell may be chondrocyte; fibrochondrocyte; osteocyte;osteoblast; osteoclast; synoviocyte; bone marrow cell; stromal cell;stem cell; embryonic stem cell; precursor cell, derived from adiposetissue; peripheral blood progenitor cell; stem cell isolated from adulttissue; genetically transformed cell; or a combination thereof. Inanother embodiment, a precursor cell may refer to a combination ofchondrocytes and other cells; a combination of osteocytes and othercells; a combination of synoviocytes and other cells; a combination ofbone marrow cells and other cells; a combination of mesenchymal cellsand other cells; a combination of stromal cells and other cells; acombination of stem cells and other cells; a combination of embryonicstem cells and other cells; a combination of precursor cells isolatedfrom adult tissue and other cells; a combination of peripheral bloodprogenitor cells and other cells; a combination of stem cells isolatedfrom adult tissue and other cells; and a combination of geneticallytransformed cells and other cells. In one embodiment of the presentinvention, the precursor cells for use in the method of the presentinvention are prepared from an organ tissue of the recipient mammal(i.e. autologous), or a syngeneic mammal. In another embodiment,allogeneic and xenogeneic precursor cells may be utilized.

In one embodiment, the scaffold of this invention incorporates stem orprogenitor or precursor cells. Such cells can be obtained directly froma mammalian donor, e.g., a patient's own cells, from a culture of cellsfrom a donor, or from established cell culture lines. In someembodiments, the mammal is a mouse, rat, rabbit, guinea pig, hamster,cow, pig, horse, goat, sheep, dog, cat, monkey, ape or a human. Cells ofthe same species and/or of the same immunological profile can beobtained by biopsy, either from the patient or a close relative. Usingstandard cell culture techniques and conditions, the cells are thengrown in culture until confluent and used when needed. The cells may becultured until a sufficient number of cells have been obtained for aparticular application.

In one embodiment, the scaffold of this invention incorporates any cellwhich may participate in cartilage repair. In some embodiments, suchcells represent autografts, in that cells are cultured ex-vivo to seedthe cells on the scaffolds of the invention, and such seeded scaffoldsare implanted into the subject.

In some embodiments, such cells may represent allografts or xenografts,which may be incorporated within the scaffolds of this invention andimplanted within a site of repair.

In one embodiment, a coral of this invention comprises a cell populationfrom in vitro culture of the coral for a time period sufficient to seedthe cells in the coral. In one embodiment, the cell population is amesenchymal stem cell population. In one embodiment, the cell may bechondrocyte; fibrochondrocyte; osteocyte; osteoblast; osteoclast;synoviocyte; bone marrow cell; stromal cell; stern cell; embryonic stemcell; precursor cell, derived from adipose tissue; peripheral bloodprogenitor cell; stem cell isolated from adult tissue; geneticallytransformed cell; or a combination thereof. In another embodiment, aprecursor cell may refer to a combination of chondrocytes and othercells; a combination of osteocytes and other cells; a combination ofsynoviocytes and other cells; a combination of bone marrow cells andother cells; a combination of mesenchymal cells and other cells; acombination of stromal cells and other cells; a combination of stemcells and other cells; a combination of embryonic stem cells and othercells; a combination of precursor cells isolated from adult tissue andother cells; a combination of peripheral blood progenitor cells andother cells; a combination of stern cells isolated from adult tissue andother cells; and a combination of genetically transformed cells andother cells. In one embodiment of the present invention, the precursorcells for use in the method of the present invention are prepared froman organ tissue of the recipient mammal (i.e. autologous), or asyngeneic mammal. In another embodiment, allogeneic and xenogeneicprecursor cells may be utilized. In one embodiment, the mesenchymal stemcells seeded in vitro are transformed. In one embodiment, the cellpopulation comprises a cell population beneficial for cartilage repair.In one embodiment, the culture comprises a chelator. In one embodimentof this invention, the chelator in a culture comprises a calciumchelator.

In one embodiment, a method of this invention induces or enhancescartilage repair, wherein the method comprises implanting in a subject,a scaffold of this invention within a site of cartilage repair, whereina region of the scaffold penetrates through a bone, resulting in theregion inserting within a bone marrow, proximal to the site of cartilagerepair.

In one embodiment, the phrase “cartilage repair” refers to restoring acartilage defect to a more healthful state. In one embodiment, restoringcartilage results in regeneration of cartilage tissue. In oneembodiment, restoring cartilage results in regeneration of a partial orfull thickness articular cartilage defect. In one embodiment, restoringcartilage results in partial or complete regeneration of cartilagetissue at a site of cartilage repair. In one embodiment, cartilagerepair may result in restoration/repair of missing or defective bonetissue as well. In one embodiment, cartilage repair comprises restoringcartilage defects of joints (e.g. knee, elbow, hip joints, shoulder,ankle), of ears, of a nose, or of a wind pipe.

In one embodiment, a method of this invention comprises inducing andenhancing cartilage repair wherein implanting a scaffold of thisinvention within a site of cartilage repair influences and improvescartilage repair.

In one embodiment, a method of this invention induces or enhancescartilage repair, by stably implanting a region of a scaffold within abone marrow so that the region of the scaffold is now proximal to a siteof enrichment of mesenchymal stem cells.

One skilled in the art will recognize that as methods of this inventionimplant a scaffold of this invention within a site of cartilage repairand wherein a region of the scaffold is inserted within a bone marrow,the scaffold formally connects the hone marrow tissue milieu with thesite of cartilage repair.

In one embodiment, a method of this invention induces or enhancescartilage repair, wherein the region inserting within a bone marrowattracts a population of cells from the bone marrow to the scaffold,thereby influencing or improving cartilage repair. In one embodiment, amethod of this invention induces or enhances cartilage repair, whereinthe region inserting within a bone marrow attracts mesenchymal stemcells from the bone marrow.

The 3-D architecture and chemical composition of a coral scaffold ofthis invention are of great importance fur both specifically positioningand confining a scaffold within a site of cartilage repair and forcellular recognition, adhesion, proliferation and differentiation ofcell populations which induce or enhance cartilage repair. Example 3,described below, demonstrates that implanting a scaffold within a siteof cartilage repair so that it forcibly contacts tissue at the site andis stably implanted within a bone marrow proximal to the site ofcartilage repair, attracts mesenchymal stem cells to the scaffold andsupports adhesion, growth, proliferation and differentiation of thesemesenchymal stem cells into cartilage tissue without any need foradditional growth promoting factors or any other inducers.

Therefore, in one embodiment a method of this invention induces orenhances cartilage repair, wherein implanting in a subject a scaffold ofthis invention promotes adhesion, proliferation or differentiation, or acombination thereof, of a cell population onto the scaffold. In oneembodiment, a method of this invention induces or enhances cartilagerepair, wherein implanting in a subject a scaffold of this inventionpromotes adhesion, proliferation or differentiation, or a combinationthereof of mesenchymal stem cells from a bone marrow. In one embodiment,a scaffold of this invention utilized in a method of this inventioncomprises a seeded cell population prior to being implanted in asubject. In one embodiment, a method of this invention induces orenhances cartilage repair, wherein implanting in a subject a scaffold ofthis invention promotes adhesion, proliferation or differentiation, or acombination thereof of transformed mesenchymal stem cells. In oneembodiment, a method of this invention induces or enhances cartilagerepair, wherein implanting in a subject a scaffold of this inventionpromotes blood vessel formation.

In one embodiment, a method of this invention induces or enhancescartilage repair, wherein an exposed surface of a scaffold of thisinvention is maximized such that a cell populations has a maximalsurface area for adhesion, growth, proliferation or differentiation, ora combination thereof. In one embodiment, a method of this inventioninduces or enhances cartilage repair, wherein an exposed surface of ascaffold of this invention is maximized such that maximal contact ismade between the scaffold of this invention and a site of cartilagerepair.

In one embodiment, a scaffold utilized in methods of this inventioncomprises at least a region which specifically positions and confinesthe coral scaffold at an optimal depth and angle within a site ofcartilage repair, such that implanting the scaffold in a subject inducesor enhances cartilage repair. In one embodiment, methods of thisinvention position and confine a scaffold of this invention within asite of cartilage repair such that a region of the scaffold comprises astable insertion within a bone marrow. In one embodiment, methods ofthis invention comprise positioning a coral of this invention at anoptimal depth and angle within a site of cartilage repair such that thedepth and angle of the coral result in a region of a scaffold comprisinga stable insertion within a bone marrow. In one embodiment, a scaffoldutilized in methods of this invention comprises at least a region whichspecifically positions and confines the coral at an optimal depth andangle within a site of cartilage repair, such that implanting thescaffold maximizes the contact area between a scaffold of this inventionand a site of cartilage repair.

In one embodiment, a scaffold utilized in methods of this inventioncomprises a shape comprising cylinder, cone, rectangular bar, plate,disc, pyramid, granule, ball, cube, tack, or a screw presented in FIG.4.

In one embodiment, a scaffold utilized in a method of the presentinvention may be used to adsorb or bind, and deliver, othertherapeutically active substances which assist in the cartilage repairor regeneration process, or which have other desired therapeuticactivity. Such substances include, by way of example, known synthetic orsemisynthetic antibiotics which may be introduced into the pore cavitiesof the shaped product or structure, or a growth factor such astransforming growth factor or one of the bone morphogenic proteins whichcan be used to assist or promote bone growth.

In any of the embodiments herein, scaffolds for use in the methods ofthe present invention may further comprise, or be implanted with, othercompounds such as, for example, antioxidants, growth factors, cytokines,antibiotics, anti-inflammatories, immunosuppressors, preservative, painmedication, other therapeutics, and excipient agents. In one embodiment,examples of growth factors that may be administered in addition to theHMG-CoA reductase inhibitor include, but are not limited to, epidermalgrowth factor (EGF), transforming growth factor-alpha (TGF-α),transforming growth factor-beta (TGF-β), human endothelial cell growthfactor (ECGF), granulocyte macrophage colony stimulating factor(GM-CSF), bone morphogenetic protein (BMP), nerve growth factor (NGF),vascular endothelial growth factor (VEGF), fibroblast growth factor(FGF), insulin-like growth factor (IGF), cartilage derived morphogeneticprotein (CDMP), platelet derived growth factor (PDGF), or anycombinations thereof. Examples of antibiotics include antimicrobials andantibacterials.

In one embodiment, a method of this invention comprises implanting ascaffold of this invention in a subject afflicted with a cartilagedefect or disorder. In some embodiments, the scaffolds are particularlysuitable for implantation in cartilage/bone defect via minimallyinvasive procedure, for example, arthroscopy.

In one embodiment, the term “implanting” refers to inserting and fixinga scaffold of this invention with in a living site in a subject, thesite comprising a site of cartilage repair. In one embodiment, a methodof this invention optimally implants a scaffold of this invention suchthat a region of the scaffold comprises a stable insertion within a bonemarrow. In one embodiment, a method of this invention implants ascaffold such a region of the scaffold now has access to mesenchymalstern cells, nutrients, blood vessels, or effector compounds, or anycombination there of. In one embodiment, a method of this inventioncomprises implanting in a subject a scaffold of this invention, whereinthe method results in removing a region of a bone and/or other tissue sothat a region of the scaffold penetrates through the bone and/or othertissue to reach a bone marrow.

A clinician skilled in the art will recognize that methods of thisinvention, which entail implanting a scaffold within a site of cartilagerepair, may require preparation of a site of cartilage repair. Thesepreparations may occur prior to implantation of a scaffold orsimultaneously with implantation. For example, bone tissue and/or othertissues proximal to a site of cartilage repair may initially be drilledthrough to reach a bone marrow, creating a channel of dimensionsappropriate for a scaffold used in the methods of this invention. Thenthe scaffold is implanted within the site so that a region of thescaffold penetrates the drilled bone tissue and extends into the bonemarrow. Alternatively, the scaffold may be attached to a tool of thisinvention capable of penetrating through bone or other tissues, or acombination thereof. In this case, as the tool penetrates through thebone tissue to reach the bone marrow, the attached scaffold issimultaneously implanted so that a region of the scaffold penetratesinto the bone marrow.

In some embodiments, following implantation of the scaffold within arepair site, or several scaffolds within the repair site, the scaffoldis processed to optimize incorporation and optimal cartilage repair. Insome embodiments, such processing may comprise cutting, sanding orotherwise smoothing the surface of the scaffold or scaffolds, foroptimal repair.

In one embodiment, methods of this invention comprise implanting ascaffold in a human subject.

In one embodiment, methods of this invention comprise implanting ascaffold in a non-human mammalian subject. In one embodiment, methods ofthis invention comprise implanting a scaffold in a horse, a race horse,a cow, a steer, a pig, a sheep, a farm animal, a rabbit, a pet, a dog, amonkey, an ape, a bird or a cat.

In one embodiment, methods of this invention are utilized for induced orenhanced repair of a cartilage defect or disorder. In one embodiment,the cartilage defect results from a trauma, a tear, a sports injury, afull or partial thickness articular cartilage defect, a joint defect,avascular necrosis, osteochondral defect, or a repetitive stressesinjury (e.g., secondary damage due to cruciate ligament injury). In oneembodiment, the cartilage disorder comprises a disease of the cartilageor the subchondral bone. In one embodiment, methods of this inventioninduce or enhance cartilage repair in osteoarthritis, rheumatoidarthritis, aseptic necrosis, avascular necrosis, osteochondral defects,osteochondritis dissecans, articular cartilage injuries, chondromalaciapatella, chondrosarcoma, chondrosarcoma-head and neck, costochondritis,enchondroma, hallux rigidus, hip labral tear, osteochondritis dissecans,torn meniscus, relapsing polychondritis, canine arthritis, fourthbranchial arch defect or cauliflower ear. In one embodiment, methods ofthis invention induce or enhance cartilage repair in degenerativecartilagenous disorders comprising disorders characterized, at least inpart, by degeneration or metabolic derangement of connective tissues ofthe body, including not only the joints or related structures, includingmuscles, bursae (synovial membrane), tendons, and fibrous tissue, butalso the growth plate, meniscal system, and intervertebral discs.

In one embodiment, a cartilage defect or disorder repaired by themethods of this invention utilizing a scaffold and/or at least a tool ofthis invention, comprises a joint of a subject (e.g. a knee, elbow,ankle, shoulder or hip joint), a rotator cup, an ear, a nose, awindpipe, a pelvis, or any other site of cartilage defect found withinthe subject.

In one embodiment, the 3-D shape and chemical composition of a scaffoldof this invention, used in the methods and/or kits of this inventionwill be determined by skilled clinicians, based on factors such as exactnature of the condition being treated, the severity of the condition,the age and general physical condition of the subject, body weight, andresponse of the individual subject, etc.

In one embodiment, the specific positioning of a scaffold of thisinvention during methods of this invention will be determined by skilledclinicians, based on factors such as exact nature of the condition beingtreated, the severity of the condition, the age and general physicalcondition of the subject, body weight, and response of the individualsubject, etc.

In one embodiment, methods of this invention are evaluated by examiningthe site of cartilage tissue repair, wherein assessment is by histology,palpation, endoscopy, arthroscopy, or imaging techniques comprisingX-ray photographs, computerized X-ray densitometry, computerizedfluorescence densitometry, magnetic resonance imaging, or another methodknown in the art, or any combination thereof.

In one embodiment, this invention provides an instrument to aid incartilage repair comprising a tool to guide a scaffold of this inventionto an optimal angle at a site of cartilage repair, a tool to guide ascaffold of this invention to an optimal angle at a site of cartilagerepair, a tool to deliver a scaffold of this invention to a site ofcartilage repair, a tool to insert a scaffold of this invention at asite of cartilage repair so that the scaffold penetrates through a bone,and inserts within a bone marrow, proximal to said site of cartilagerepair, a tool to release a scaffold of this invention at a site ofcartilage repair, or a tool able to provide a combination thereof,whereby the tool may be separated from the scaffold following placementof the scaffold within a site of cartilage repair.

In one embodiment, the instrument of this invention comprises at least asingle tool. Example 4 provides some examples of envisioned tools ofthis invention. The tools are versatile, in that, in one embodiment, asingle tool may comprise 2 elements, which are useful for creatingaccess to the cartilage/bone defect and inserting the scaffold therein,or in some embodiments, the same tool comprises different adaptor tinsto achieve the same.

In one embodiment, methods of this invention utilize a tool of thisinvention such that at a site of cartilage repair preparations forimplanting a scaffold of this invention comprise drilling through tissueto reach a bone marrow. In one embodiment, the tissue to be drilled iscartilage tissue, bone tissue, connective tissue, muscle tissue or bonemarrow tissue or any combination thereof. One skilled in the art willrecognize that selection of a tool will depend upon the tissue beingpenetrated.

In one embodiment, methods of this invention utilize an instrument ofthis invention, wherein implanting a scaffold of this inventioncomprises specifically positioning and confining the coral at an optimaldepth and angle within a site of cartilage repair. Uniquely andrepresenting one embodiment of the invention, the tools of thisinvention allow for implantation of the scaffold at a desired angle, orunder arthroscopic conditions, in order to minimize for example, therisk of infection.

In some embodiments, such tools may comprise a tool for insertion of ascaffold into a repair site, which tool is specifically constructed tohold the scaffold and optimally position it within the site. In someembodiments, multiple tools for different sized or shaped scaffolds maybe incorporated within kits of the invention, to accommodate theimplantation of varied scaffolds within a site or sites of cartilagerepair. In some embodiments, the kits of this invention will comprise atool to process the scaffold following insertion within the site ofrepair, to effect a smooth optimal surface for optimal cartilage repair.In some embodiments, the kits of this invention may further comprise atool for creating a void between the repair site and a source ofmesenchymal stem cells. In some embodiments, the kits may comprise apiece, which inserts within a common tool to effect such a void, forexample, a drill bit is included in the kits of this invention of a sizeand depth to easily and appropriately drill through nearby bone in orderthat the scaffolding may be inserted in a site of cartilage repair,where at least a portion of the scaffold, or contiguous scaffolds insertwithin a site of cartilage repair and reach underlying bone marrow, toserve as a source for migrating mesenehymal stem cells to effectcartilage repair.

One skilled in the art will recognize that the path created by drillingthrough tissue to reach a bone marrow is such that it allows for ascaffold of this invention to reach the bone marrow and be stablyimplanted at this site. The scaffold must be sufficiently secured withina site of cartilage repair so that it does not get dislodged as a jointarticulates. A clinician skilled in the art will also recognize that theextent of a drilled path is such that a scaffold is securely held butthe path is not so extensive to incur increased damage to surroundingtissue.

Preparation of a site of cartilage repair may also involve removingdamaged cartilage or bone tissue, or a combination thereof. Therefore,in one embodiment, a tool of this invention drills a path such thatdamaged tissue at the site of repair or proximal to a site of repair isremoved.

In one embodiment, a scaffold of this invention comprises a regionfitted to a tool provided by an instrument of this invention. In oneembodiment, the region fitted to a tool comprises cutting a single pieceof coral to comprise a fitted region. In one embodiment, the regionfitted to a tool comprises a region formed in a polymer coating.

A tool of this invention may therefore prepare the pathway a scaffoldwill follow, guide the scaffold being implanted, and implant thescaffold concurrently. By concurrently preparing the site and implantingthe scaffold, the time of invasive surgery a subject is subjected to maybe shortened.

In one embodiment, a region of the scaffold separates from the toolfollowing placement of the scaffold within the site of cartilage repair.In one embodiment, the region separates from the tool, whereinseparation of the tool from the scaffold comprises UV light-activatedseparation, LASER-activated separation, torsion-dependent separation orchemically-activated separation or a combination thereof. In oneembodiment, separation of the tool from the scaffold leaves behind thescaffold specifically positioned within a site of repair for induced orenhance cartilage repair. The mechanism for separation should also notcause additional trauma to a site of repair.

In one embodiment, separation of the tool from the scaffold results inthe scaffold being specifically positioned and confined at an optimaldepth and angle within a site of cartilage repair. In one embodiment,separation of the tool from the scaffold results in the scaffold beingimplanted in a subject within a site of cartilage repair, wherein aregion of the scaffold penetrates through a bone, results in the regioninserting within a bone marrow, proximal to the site of cartilagerepair.

In one embodiment, this invention provides a kit for repair of tissuecomprising the scaffold of this invention, at least a tool of thisinvention, and directions for utilizing the scaffold in tissue repair.

One skilled in the art will recognize that choice of a kit by a skilledclinician would be dependent upon factors such as exact nature of thecondition being treated, the severity of the condition, the age andgeneral physical condition of the subject, body weight, and response ofthe individual subject.

Thus, in one embodiment, the scaffold comprised in a kit of thisinvention comprises different sizes, shapes or chemical compositions, ora combination thereof. In one embodiment, this invention provides a kitfor cartilage repair comprising a scaffold of this invention, at least atool of this invention, and directions for utilizing the scaffold incartilage repair.

In one embodiment, methods of this invention utilize a scaffold of thisinvention with at least a tool of this invention to repair a site ofcartilage repair in a subject, wherein a tool is used to drill within orproximal to a site of cartilage repair to provide access to a bonemarrow, followed by the tool specifically implanting a scaffold of thisinvention within the site of cartilage repair, wherein a region of thescaffold penetrates into the bone marrow, wherein regeneration ofcartilage or bone tissue or a combination thereof occurs. In oneembodiment, methods of this invention may utilize a scaffold of thisinvention shaped at the time of drilling. In one embodiment, methods ofthis invention may simultaneously drill and implant a scaffold of thisinvention within a site of cartilage repair.

The architectural and chemical attributes of a 3-D coral scaffold ofthis invention so far described, may also be found in a scaffold formedfrom a polymer form enveloping coral particles. Therefore, in oneembodiment, a scaffold of this invention for tissue repair comprises apolymer form enveloping coral particles.

In one embodiment, the polymer form comprises a flexible polymer form.In one embodiment of this invention, the term “flexible” refers to thecapability of a polymer form to adapt to the requirements at a site oftissue repair. In one embodiment, the polymer form comprises a flexiblepolymer form at the time of implanting within a site of tissue repairand hardens over time. In one embodiment, the polymer form remainsflexible for the life-time of the scaffold.

In one embodiment, a flexible polymer form adapts to the requirements ata site of tissue repair such that contact between a scaffold and a siteof tissue repair is maximized. In one embodiment, a flexible polymerform adapts to the requirements at a site of tissue repair such that aregion of a scaffold positions and confines the polymer envelope at anoptimal depth and angle within a site of tissue repair. In oneembodiment, a flexible polymer form adapts to the requirements at a siteof tissue repair such that a region of a scaffold penetrates through abone, resulting in the region inserting within a bone marrow, proximalto the site of tissue repair.

In one embodiment, the polymer form comprises a rigid polymer form. Inone embodiment of this invention, the term “rigid” refers to a polymerenvelope having a fixed framework. In one embodiment of this invention,a rigid polymer envelope may comprise all of the shape characteristicsof a single piece of coral listed above.

In one embodiment, the polymer form maximizes surface area of thescaffold in contact with a site of implantation. In skilled in the artwill recognize that similar to a scaffold shaped from a single piece ofcoral, maximizing surface area of a polymer form enveloping coralparticles maximizes the area available to a mesenchymal stem cellpopulations at a site of tissue repair. In one embodiment, the maximalsurface area is available to a mesenchymal stem cell population and/orchondrocytes and/or osteoblasts.

In one embodiment, the coral particles enveloped in a polymer forms aremicronized to 1-10 μm or 5-20 μm or 10-50 μm in size.

In one embodiment, the coral particles comprise a same sources of coralas used for a scaffold comprising a single piece of coral.

In one embodiment, the polymer form of this invention comprises a samesources of polymer as used for a polymer coating of a single piece ofcoral.

In some embodiments, the term “comprise” or grammatical forms thereof,refers to the inclusion of the indicated components of this invention,as well as inclusion of other active agents, and pharmaceuticallyacceptable carriers, excipients, emollients, stabilizers, etc., as areknown in the pharmaceutical industry.

In one embodiment, the present invention provides combined preparations.In one embodiment, the term “a combined preparation” defines especiallya “kit of parts” in the sense that the combination partners as definedabove can be used independently or in different combinations i.e.,simultaneously, concurrently, separately or sequentially.

EXAMPLES Example 1 Preparation of Coral Scaffolding

Coral is collected from the hydrocoral Millepora dichotoma, which has anaverage pore size of 150 μm and density of 1.7 g/cm³. Three-dimensional(3-D) coral scaffold implants of the desired shape are prepared fromthis material by first cutting and polishing the coral. This provides ashaped coral form without unwanted sharp edges. Following thismechanical processing, the coral is soaked twice in 4% HCl for 15 mineach time, and is then treated with 4 M NaOH to remove trappedparticles, debris and organic remnants. The coral is then autoclaved andtreated by gas sterilization prior the surgical procedure.

The coral scaffold implants are inserted into osteochondral defectsproduced by drilling in the weight-bearing area of the medial femoralcondyle of mature goats, sheep, horses, dogs and monkeys. The implantsare tightly fitted into the defect and the excess length cut away to thelevel of the articular cartilage. In this way, the coral scaffold isgrafted through two types of tissue, cartilage and subchondral bone.

The animal subjects are examined and observed over an extended timeperiod, post arthroscopic surgery. The untreated knee of each animal isused as a control for comparisons following these surgeries. Atappropriate intervals animals are sacrificed and necroscopy performed.Appropriate time periods for examining the site of cartilage repair are4, 8, and 16 weeks post surgery. At this time, the articular surfacesare photographed and tissue is removed from the site of repair andprepared for histological observations. Specifically, a block consistingof the grafted area and the surrounding tissue is removed using a finesaw. The material is further processed for routine histology, whichincludes slow decalcification in 22% sodium citrate-buffered formic acidand staining of 5 mm thick transverse sections using haematoxylin andeosin.

Example 2 Coral Scaffolding Containing as Partial or DiscontinuousPolymer Coating Materials and Methods

Coralline scaffolds further comprising a hydrogel containing 1%, 3%, 5%and hyaluronic acid (HA) were prepared.

1%, 3%, 5% and 10% hyaluronic acid (HA) solutions were prepared andmixed overnight on a shaker at room temperature. The resulting gels wereapplied to funnels containing tight-fitted coralline scaffolds/plugs andthe amount of scaffold in contact with the gel varied. The funnel systemwas then spun in a centrifuge for 10-20 minutes at 10000 RPM, andscaffolds were then heated at 50° C. for 30 minutes, frozen at −80° C.for two hours and lyophilized at 30-40 mtorr, −100° C. overnight.

Results

FIG. 5A is a photograph showing scaffold insertion and tight fittingwithin a funnel as described, which results in exposure of a portion ofthe scaffold to what is applied to the funnel, as shown in FIG. 5B,where an HA hydrogel is applied to the funnel. In FIG. 5B, spinning thefunnel containing scaffold with the HA hydrogel results in goodincorporation of the hydrogel within the scaffold.

Varying the time and speed at which the funnel is spun controlled thepenetration depth of the HA in the gel. FIG. 5E shows less penetrationwithin the scaffold when the apparatus described was spun for 7 minutes,and FIG. 5D shows the penetration obtained when the apparatus was spunfor 10 minutes, in comparison to 20 minutes, as shown in FIG. 5C. Thestaining evident is Safranin O, which stains hyaluronic acidincorporated in the scaffolds.

Lyophilized scaffolds may be desired for use. FIGS. 6 and 7 depictlyophilized scaffolds, comprising an upper layer staining with SafraninO, and a lower layer without stain, indicating HA incorporation withinthe upper scaffold layer. In some embodiments of this invention, suchscaffolds are desirable, whereby the HA-enriched layer is placedproximal to cartilage and the HA-deficient or poor layer is placedproximal to bone and/or in the bone marrow. FIG. 7 further depicts anoven-dried scaffold and the difference in HA distribution as aconsequence of the drying method utilized.

Light microscopic evaluation of 1% (FIG. 8A) and 3% (FIG. 8B) HAscaffolds show HA particles 8-10 distributed in a dot pattern, coatingthe exposed surfaces of the scaffolds. For example: the average coatedarea of a 1% hydrogel scaffold preparation was about 2.3 square micrometer, while the average coated area in a 3% hydrogel scaffold was 3.4square micro meter (about 50-70 spots evaluated).

Example 3 Restoration of an Osteochondral Defect

Restoration of an osteochondral defect is performed in mature dogs usingrounded implants 3.5 mm in diameter and 6 mm in length. A 3×7 mm core ofcartilage and bone tissue is drilled out of the medial femoral condyleof each dog and the implant fitted into the site of cartilage repair(for example, as depicted in FIGS. 9A and 9B). Animals are harvested atvariable time points post implantation; for example, 4, 8 and 16 weekspost surgery.

Analysis after one month shows that the implant is well incorporatedinto the articular cartilage creating a continuous smooth surface. Theinterface between the implant and the surrounding tissue is stillvisible, but the upper part of the implant has already been invaded andpartial degradation of the implant material is observed. Histologicalsections reveal a void area in which the carbonated hydroskeletalmaterial was decalcified.

Examination after two months shows some remnants of the biomaterial arestill be detectable on the surface articular cartilage but well-definedorganization of the chondral and subchondral tissue is also seen.

By 4 months, the implant material inserted in the chondral andsubchondral area has been totally replaced by new cartilage and bonetissue. A well-defined tidemark is visible at the interface between thechondral and the subchondral tissue, and columnar chondrocytes andosteocytes are found in the subchondral area, similar to what isobserved in a section taken from the untreated knee.

Example 4 Implantation Tools for Joint Repair

Insertion of the scaffolds of this invention into a site of joint and/orbone repair may be via the use of specialized tools. A schematic exampleof one embodiment of a tool utilized in the insertion of a scaffold ofthis invention is depicted in FIG. 10A. A harvester 10-1 has areplaceable adaptor which may contain a blade edge 10-4, whichfacilitates the penetration of cartilage and bone with the applicationof mechanical force. The tool may comprise a replaceable puncher head10-5. The tool may further comprise an indicator 10-3, which serves todelineate the depth at which the instrument is inserted, and therebyavoid too deep insertion within the bone, or alternatively to indicatethat the appropriate depth penetration has not been attained.

FIG. 10B demonstrates another embodiment of the tool, which shows across section along the long axis of the tool, which shows in thisembodiment, the presence of a hollow extending along the length of thetool. Through this hollow, it is possible to insert a leading wire, suchas a K-wire, or other leading device, which helps stabilize the toolduring insertion of the scaffold, for example.

FIGS. 11A-11C schematically depict another embodiment of a tool of thisinvention, in this case a tool insert, which may be inserted in theHarvester shown in FIG. 10A. The insertion body 11-2 depicted in FIG.11A will further comprise a grooved hollow 11-3, which accommodatesinsertion of a scaffold within the hollow. The insertion body edge 11-4may be modified to be smooth to avoid piercing any tissue duringimplantation of the scaffold contained therewithin. When the implant isloaded within the insert, the plunger or piston 11-1 pushes the implantout of the tool insert and into the site of repair, in for example, ahole made by the harvester of FIG. 10A.

FIGS. 12A-12C schematically depict an embodiment of an adjustabledelivery system of this invention. FIG. 12A depicts the plunger orpiston 12-1 placement within the body of the tool 12-2 which angles viaattachment of a joint 12-3 about 50-2 mm from the edge providing easyaccess to a hard to reach areas, for example, inside the knee, whenperforming the arthroscopy or other procedures meant to be minimallyinvasive. This joint can be either adjustable or replaceable with adifferent angle parts, for example, as depicted in FIGS. 12B and 12C,showing 12-4, which can be a replaceable locking head. FIG. 12D providesan enlarged detailed view, where an adjustable or replaceable joint 12-5is proximal to a groove, 12-6, which houses the implant during theimplantation and which may facilitate identification of positioning ofthe implant during implantation, which joint may comprise a rounded edge12-7 to minimize the trauma to tissue during implantation

Another embodiment is shown in FIG. 13A, a cross section along axis 13-1-13-2, which tool is semi-elastic. The elastic spring, or other strongand elastic material 13-3, transfers the force from the piston to thebit drill or to the inserted implant 13-4.

The insertion system is a syringe like system. The implant is loaded atthe tip and the piston pushes the implant out and into the pre-createdhole (defect) made by the harvester.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1.-76. (canceled)
 77. A shaped platform for repair of cartilage or anosteochondral defect comprising at least a first portion of an exposedsurface, which first portion is raised with respect to at least a secondportion of said exposed surface in said shaped platform, wherein said atleast a first portion of said shaped platform is proximal to a hollow orhollows along a longitudinal axis of said first portion and wherein saidat least a second portion abuts said hollow or hollows and wherein saidfirst portion comprises at least a region, which specifically positionsand confines said shaped platform within a site of cartilage repair. 78.The shaped platform of claim 77, wherein said shaped platform furthercomprises a polymer coating.
 79. The shaped platform of claim 78,wherein said polymer coating is permeable.
 80. The shaped platform ofclaim 78, wherein said polymer coating is discontinuous and optionallyin the form of aggregates or particles.
 81. The shaped platform of claim78, wherein said polymer comprises a natural polymer comprisingcollagen, elastin, silk, hyaluronic acid, chitosan, or any combinationsthereof.
 82. The shaped platform of claim 81, wherein said collagen orhyaluronic acid is cross-linked.
 83. The shaped platform of claim 77,wherein said shaped platform further comprises a cytokine, a bonemorphogenetic protein (BMP), a chelator, a cell population, atherapeutic compound, an antibiotic, or any combination thereof.
 84. Theshaped platform of claim 83, wherein said shaped platform furthercomprises allogeneic cells.
 85. The shaped platform of claim 83, whereinsaid therapeutic compound comprises an anti-inflammatory compound, anantibacterial compound, an antiviral compound, an antifungal compound,an antiparasitic compound, a growth factor, a pro-angiogenic factor or acombination thereof.
 86. The shaped platform of claim 77, wherein theshaped platform approximates a cone, a tack, a screw, a cylinder, arectangular bar, a plate, a disc, a pyramid, a granule, a ball or a cubein shape.
 87. The shaped platform of claim 77, wherein at least aportion of said shaped platform penetrates through a bone, resulting insaid portion inserting within a bone marrow proximal to a site ofcartilage or osteochondral repair.
 88. A method of inducing or enhancingcartilage repair, said method comprising implanting in a subject, ashaped platform of claim 77 within a site of cartilage repair in saidsubject, wherein a region of said shaped platform penetrates through abone, resulting in said region inserting within a bone marrow, proximalto said site of cartilage repair in said subject.
 89. The method ofclaim 88, wherein said subject is afflicted with a cartilage defect ordisorder wherein said cartilage defect or disorder comprises a full orpartial thickness articular cartilage defect, osteoarthritis,osteochondritis, avascular necrosis, or a joint defect resulting fromtrauma, sports, a disease of the cartilage or the subchondral bone, orrepetitive stress.
 90. A method of treating an osteochondral defect in asubject, said method comprising implanting in a subject, a shapedplatform of claim 77 within a site of osteochondral defect in saidsubject, wherein a region of said shaped platform penetrates through abone, resulting in said region inserting within a bone marrow, proximalto said site of osteochondral defect in said subject.